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– What is biology - rick mercer resident doctor mercer paramedicWellness and HomeostasisIn this unit we will focus on wellness and homeostasis and show how our body’s ability to adjust to fluctuations can help us stay well.What is wellness?Wellness is not just about being healthy and eating right. It’s a lifestyle that takes care of your mind, body and spirit.Physical wellness - includes caring for your body in terms of exercise, eating right, sleep, massage, doctor check ups, chiropractor, taking vitamins/medicine, hygiene - boring but good - Why do we have to sleepEmotional wellness – involves the existence of healthy emotions as we experience the events on our lives. We can help our emotional state with the following activities - stress release, taking a long walk, listening to music, playing sports, video games, yoga, talking to someone, diary, breakdancing, reconstructive surgery, hobbySocial wellness – refers to the degree to which a person interacts successfully with others. We can increase our social wellness by working on - relationships with family and friends, community help, volunteering, matchmaking, joining a club, socializing with others, making new friendsSpiritual Wellness – refers to the human need to understand the deeper meanings of life and a search for themselves. We can work on or spiritual wellness by taking time to meditate, reflect, prayer- during this time we learn a lot about ourselves, our bodies, our health, being in nature, talking and reading about spirituality.Intellectual Wellness – refers to being able and willing to learn new things and challenge your mind. We can work on this by training your mind, reading, puzzles, certain video games, inquiry, staying in school, experiencing new things, playing an instrument, competitions, taking challenging coursesEnvironmental Wellness – refers to your awareness to caring for the world around you. We can work on this by - decluttering, taking care of the earth, being aware of hazards affecting the earth and living acccordingly , recycling, consuming environmentallyWELLNESS CHECK IN - hypertrichosis - boy who dies if he falls asleep - allergic to sunlight - sleep nova – what would happen if you didn’t sleepAdd stress video hereshorter stress video animated Journal – 10 marks Characteristics of Life’s aliveBiology is the study of life. All living things have these 6 characteristics:Living things are organized. cells – tissues – organs – systems – organismLiving things take materials and energy from the environment. (eat/breathe)Living things can control and adapt. (homeostatic)Living things reproduce.Living things respond to stimuli.Living things grow and develop.A Cold WalkBefore leaving the house you put on your winter outwear – boots, mitts, hat, scarf, parka. This increased amount of clothing traps body heat and you begin to sweat as your body tries to cool down. As you leave the house and enter the cold winter air, your exposed cheeks feel cold. Near the end of the walk you notice your toes and fingers beginning to feel numb. You’re late, so you run the rest of the way to school. When you arrive, you are glad to find the run has warmed up your fingers and toes. However, as you walk through the hallway to your locker you find yourself beginning to sweat again. You remove your winter outerwear at your locker and head to class.A few minutes later you find yourself becoming cold and you begin to shiver as your body tries to warm up. - Sheldon - homeostasis 18:45 BBC - ice man Dr Popsicle negative feedback amoeba sistersHomeostasisIn order for our bodies to function properly it must remain fairly constant at all times regardless of changes around us. Without this ability, we could not survive.Homeostasis is the ability of our body systems to maintain a constant internal environment despite changes in the external/internal environment.Some homeostatic processes include:1 – regulating respiratory gases2 – coping with pathogens3 – maintaining nutrient supply4 – repairing injuries5 – maintaining fluid and ion balance6 – coordinating responsesThe most common body constants include:Temperature - 37°C Blood pressure – 120/80 mmHgBlood pH - 7.4Blood glucose – 100 mg/mLIn other words, your body systems function best when close to these constants. There are three basic strategies that organisms use to maintain homeostasis of their body systems.Structural – The organism has specific body features to help it adjust to its environment. Eg. Birds have feathers to insulate their bodies.Functional – The organism’s body processes adjust to changes. Eg. Bears hibernating during cold months when food is scarce.Behavioural – The organism’s actions help it to maintain homeostasis. Eg. Snakes use the heat from the sun to increase their body temperature because they are cold blooded animals.When something is out of balance, the system responds to the change and brings it back to the normal set point . This is achieved through negative feedback mechanisms.Negative feedback mechanisms in the body oppose or resist change in the body’s internal conditions. We can compare these systems to a thermostat in your home. You set the constant temperature and the thermostat responds to changes outside of this range. If the temperature in the house drops below the set temperature, then the heater turns on. Once the temperature of the house is reached, then the thermostat turns the heater off.Negative feedback mechanisms have three main components:A sensor – detects the change or stimulus and sends it to the coordinating centre. The sensor is usually a sense organ or internal receptor.Different types of sensors include:Chemoreceptors – present in certain blood vessels to detect chemical changes in the body. Eg. pHPhotoreceptors – cells in the eye detect eye color, intensity and movement of light.Olfactory receptors – receptors in the nose and tongue can detect tastes and smellsBaroreceptors – monitors pressure in blood vessels and helps adjust water levels Proprioreceptors – monitors muscle contractions and can adjust for movements or changes.Eg. Bladder controlThermoreceptors – monitors and detects changes in body temperatureA coordinating centre – sends message to the area that needs to make the change (effector). Coordinating centre is usually in the nervous system or an endocrine gland.An effector – makes the change to bring the body back to normal. The effector is usually a muscle contracting or the production of a hormone. These feedback mechanisms are controlled by messages sent between the NERVOUS (brain and spinal cord) and ENDOCRINE (chemicals and hormones) systems. The hypothalamus is a section of the brain whose main function is homeostasis. The hypothalamus can produce hormones and chemicals that help control different cells and organs. It controls functions like body temperature regulation, heart rate, respiration rate, and water balance. The hypothalamus will work with the pituitary gland (endocrine system) to trigger the release of hormones and initiate changes in the body. A hormone is a chemical messenger that travels through the bloodstream to a target organ and will initiate some effect. The endocrine system is made up of all the glands that secrete hormones. (more to come later)There are many negative feedback systems throughout the body. The following are three very important systems.THERMOREGULATION This is the ability of the body to maintain a constant temperature of 37°C. If your body is too hot it will damage molecules like enzymes that you need to function. If the body is too cold, certain metabolic processes will not occur. When body heats up or cools down, sensors detect these changes and initiate effects in other parts of the body. For ex. If you are hot, the skin cells (sensor) detect a change and send a message to the hypothalamus (coordinating centre) which sends a message to the sweat glands (effector) to trigger them to release sweat and cool down the body. (see ex. negative feedback diagram)OSMOREGULATION The ability to maintain constant water balance around 60-90%.Each of our cells is composed of water and so water is necessary for our survival. A decrease by 10% can result in death. Water is obtained through our diet and via metabolic processes in the body.The body can produce urine to adjust water levels in the body. The production of urine is controlled by the kidney via negative feedback mechanisms. This is crucial to our survival. WASTE MANAGEMENT The ability of body to rid itself of harmful wastes. The liver, kidneys, skin, circulatory, digestive system are all involved in homeostasis of waste management. Chemicals are detected in the blood by chemoreceptors which then send messages to other parts of the body to make the change. Eg. respiration Study questions What are the 6 characteristics of life?Ability to reproduce, ability to grow, ability to obtain materials from environment, organized, respond to stimuli, ability to adaptWhat is homeostasis? What are some examples of processes that need to be kept constant in the body?Ability of an organism to maintain its internal environment and adapt to changes around itWater and ion regulation, repairing injuires, coping with pathogens, maintaning nutrient supply, thermoregulation, waste managementWhich two body systems work together to send the body messages? Which two organs/glands do they use to do this?Endocrine and nervous systemPituitary gland and hypothalamusWhat functions does the hypothalamus control?Homeostasis – heart rate, respiration rate, temperature/thermoregulation, osmoregulationWhat is a hormone? A chemical messenger that travels through the bloodstream to a target organ to initiate an effect. Hormones are specific to one task.What is the purpose of a negative feedback mechanism? Oppose or resist change in the body’s internal condition to keep the important body constants in check like temperature.What three basic strategies do organisms use to adjust to changes either externally or internally? Provide an example of each that is different than the notes.Structural – hair on mammalsFunctional – thermoregulationBehavioural – migrationWhat are the three main components of a negative feedback mechanism? What is the function of each component?Sensor/receptor – detects change or stimulus and send to coordinating centreCoordinating centre – sends a message to the area of the body that can make a changeEffector – receives message and makes a change in the body. Could be a muscle or a glandWhat are some examples of receptors in the body? Provide some real life examples. thermoreceptors, photoreceptors, olfactory receptors, chemoreceptors, baroreceptors, proprioreceptorsWhat is the coordinating centre for thermoregulation?hypothalamus11. What is osmoregulation? Why is it important?Ability to maintain water balance. Each of our cells is composed of water and water is the carrier for most of our moelcules, ions, etc. Without water many metabolic processes cannot occur. The Cell – The Fundamental unit of LifeIn order to keep our bodies alive and to maintain homeostasis, cells need to be able to complete all essential life processes. Each cell completes its tasks and as a whole, all of our cells help to keep us alive.Cells make up many different of organisms. Some organisms are single celled and others are multi cellular. Animal cells and plant cells are both eukaryotic cells.Cell Organelles and Functions henrietta lacks - cell video – amoeba sisters - NOVA aging - documentary on aging cells mexus Henrietta lacksEach part (organelle) of a cell has a specific job to do. Without it the cell cannot function properly which in turn means the body can be at risk leading to illness.Cell Membrane This is the outer membrane of the cell. It protects the cell. It controls movement of materials into and out of cell. It is semi-permeable (allows only some materials in and out).It has receptors for communication between cells.2. Cytoplasm (protoplasm) This is a gel like substance that surrounds all cell parts. It is composed mostly of water and some nutrients so that metabolic processes take place here (like energy production or digestion of molecules). 3. NucleusContains DNA, a molecule that carries codes for all cell functions. Nuclear Membrane It surrounds the nucleus and controls movement of substances in or out.Nuclear Pores These are small gaps in the nuclear membrane which allow for communication with cell organelles and for movement of substances out of nucleus.Nucleolus This is the center of the nucleus where RNA is created and then transported out into the cytoplasm.Chromatin A mass of DNA and proteins that condenses into chromosomes It is found in nucleus between the nuclear membrane and the nucleolus. Mitochondria These are known as powerhouses for the cell. It’s the place where cellular respiration takes place to create energy – ATP.Cells adapt to their energy needs. Cells that need high energy will have more mitochondrion. (eg. muscle cells) 5. Endoplasmic Reticulum This is a system of membranes connected to the nucleus, that act as a transport system for important macromolecules that are created at different sites around the cell. There are two specific types:SMOOTH ER - site of lipid (fat) and steroid synthesisROUGH ER – the site of protein synthesis. The ROUGH parts are the RIBOSOMESRibosomes A complex structure where proteins are synthesized/made with the help of ribosomal RNA.They are located on the rough ER or in the cytoplasm of the cell. 7. VacuoleMembrane bound sacs containing cytoplasm. They store nutrients or wastes that need to be used or released.8. Lysosomes These are small vesicles pinched off from Golgi apparatus that transport enzymes used for digestion of wastes and foreign bodies. Centrioles Structures that aid the cell during mitosis/meiosis (cell division)They are part of a larger system of microtubules that are found throughout cytoplasm. 10.Golgi ApparatusA membrane bound structure that stores, modifies, packages and transports proteins, fats, steroids, enzymes that are created at the endoplasmic reticulum. Animal Cells vs Plant CellsBoth animal and plant cells are eukaryotes meaning they are cells that contain a nucleus. But there are some major differences between the two types of cells.Animal cells do not have a cell wall. Animal cells have smaller vacuoles. Animal cells do not have chloroplasts. Study questionsWhat is an organelle?Which organelles provide protection for the cell?Which organelles manufacture substances or molecules for the cell?Which organelle is the site of energy production?Which organelles help move substances around the cell?What are the 3 differences between and animal and plant cell?Structure of Cell MembranesAll cells have a plasma membrane that separates them from surrounding materials. Similar membranes are also found inside the cells as part of the organelles – eg. endoplasmic reticulum, golgi, mitochondria,etc.The currently accepted model of the membrane is called the fluid mosaic model. This is because the membrane is flexible and has many different molecules and structures embedded within it, like a mosaic. - TED talkCell membranes have 4 functions:communication/recognitionprotectionhomeostasistransportIt is composed of a double layer of phospholipid molecules that are arranged with their heads (hydrophilic end: water attracting) facing outwards. This could be the outside or inside of cell. Their tails (hydrophobic end: water repelling) facing inwards. This double layer is fluid or flexible, which means that any molecules embedded within the structure can move around to different areas of the cell. Proteins, carbohydrates, and cholesterol are some examples of these molecules. The membrane can also be manipulated and changed without any changes to the interior of the cell. This is helpful when transporting materials in and out. Proteins: There are various types of proteins that can exist and each type has a specific cellular function.Channel/integral proteins – these span the entire width of the lipid bilayer and open up on both sides of the membrane to aid in transport of molecules in and out. Carrier proteins – selectively interact with specific molecules so that they can cross the membrane. Act as a molecule taxi.Receptor proteins - These are located on the outside of the membrane. They have specific shapes that allow only specific molecules like hormones to bind to them. These molecules carry information that triggers a response in the cell of that effector organ. Carbohydrates: Carbohydrate chains come in two forms. The chains can attach to phospholipids on the outer surface of the membrane and create glycolipids. Or they attach to proteins and create glycoproteins. These carbohydrates are responsible for giving each cell a unique identity marking. Our bodies recognize these cells as our own. Different blood types and transplanted organs have different surface markers than our own and our immune systems will recognize them as foreign and attack if necessary. These molecules will also help to stabilize the membrane.Cholesterol: Helps to stiffen the membrane and control the fluidity by preventing the phospholipid molecules from sticking together.Transport across a membraneMovement of substances across the membrane is selective due to the nature of the membrane. Small, uncharged molecules move across the membrane freely. These include oxygen, carbon dioxide. Large uncharged macromolecules like lipids, glucose and steroids need some protein channels to get into or out of the cell. Charged molecules like sodium ions (Na+) , potassium ions (K+) and chloride ions (Cl-) cannot enter the cell through the lipid bilayer. They will need to be transported via carrier proteins/ ION prehension Questions Plasma Membrane??What is the name of the plasma membrane model??Fluid mosaic model?Why do we call it this??Because it is made of up of hundreds of phospholipids that are held together in a fluid matrix and embedded within it are many different molecules like proteins and carbohydrates. The membrane is flexible and changeable.?What main molecule makes up the cell membrane?? phospholipid?Describe what this molecule looks like and how it’s arranged in the cell membrane????Phospholipids are molecules that have hydrophilic heads and hydrophobic tails. The charged heads and non charged tails arrange themselves so that the heads face the outside and the inside of the cells. They are organized into a double layer of molecules. The tails face each other and make of the inside of the membrane. What other molecules are present in this double phospholipid bilayer??Proteins, carbohydrates (glycolipid/glycoproteins) cholesterol?Why it important that the membrane remains fluid??So that the embedded molecules can move around within the membrane and so the membrane can change shape and adapt to the changes that need to occur to maintain homeostasis.?What are the three types of proteins??Receptor, carrier, channel?Which proteins act doorways for molecules??carrier and channel?Which protein?bind to hormones to cause a change in a cell or organ??receptor?What are the two types of carbohydrates??Glycolipid and glycoproteins?What is the difference between the two types of carbohydrates??Glycolipids are attached to the phospholipid heads on the putisde of the membrane while glycoproteins are attached to proteins that are embedded in the bilayer.What are the functions of these carbohydrate molecules??Carbohydrate molecules are identity markers and surface markers. They help cells communicate with each other and keep the membrane stable.?What is the purpose of cholesterol in the cell membrane??To maintain the rigidity of the membrane, and prevent phospholipids from sticking together.?How does the arrangement of the phospholipid bilayer affect transport of molecules across cells??? Because the inner layer of the cell membrane is hydrophobic, polar molecules cannot pass freely through the membrane. We need protein channels to help with movement of molecules.Which molecules can move freely across the membrane without transport proteins???Oxygen and carbon dioxideSmall, uncharged molecules (non polar)Which molecules need a helper protein to get across the membrane??Ions and large molecules, lipids, sugars?If an ion that is polar needs to get across the membrane, how does this happen??Ion pumps?How does water get across the membrane? ****?aquaporins?? amoeba sisters cell membrane transport amoeba sisters osmosis - cell membrane - transportActive and Passive Transport – Movement of Substances - amoeba sisters transport overviewConcentration gradient: when there is a higher concentration of the substance in one area and a lower concentration in another. This fuels the processes of diffusion and osmosis.Passive transport does not require energy to move molecules across the membrane. Substances follow the concentration gradient, meaning that they move from a high concentration gradient to a low one. Think of how little energy you use when walking or running downhill. That’s what passive transport is like.Types of passive transport include: Diffusion, osmosis, and facilitated diffusion.1. Diffusion: movement of substances along a concentration gradient from an area of high concentration to an area of low concentration. Diffusion will continue until the molecules are evenly distributed on both sides of the membrane. of diffusion are dependent on many factors:Surface area – the larger the surface area, the faster the processSize – smaller molecules diffuse faster – they wont need channelsTemperature – increased temperature speeds up movement of molecules across the membrane, faster diffusionConcentration Gradient – if the difference in concentration from one area to another is much larger, then the movement will be faster.Solubility – the more soluble the substance is in a lipid, the faster the rate of diffusion2. Osmosis: The tendency of water to pass through a semi permeable membrane into a solution of higher solute concentration. This will equalize the concentration of materials on both sides of the membrane. Solute is the combination of dissolved sugars, salts, proteins or other molecules that are dissolved in the solvent (water).Think of this as water moving from an area of high to low concentration of water.This becomes extremely important in the human body. The type of solution in which animal cells are floating, will affect the movement of water. There are three types of solution that can affect osmosis:Hypertonic solution: is when the solution surrounding the cell has a higher concentration of solute and a lower concentration of water than the cell itself. In this situation, water will move out of the cell by osmosis to try and balance the concentrations. The cell will shrink. Hypotonic Solution: Is when the solution surrounding the cell has a low concentration of solute and a high concentration of water, as compared to the cell. In this situation, water will move into the cell by osmosis. The cell will swell and could burst if concentration of water is very high. Recall that animal cells do not have a cell wall and so are more susceptible to bursting.Isotonic: When the concentration of solute is the same in both areas. Nothing will happen to the cell in this situation because both sides are balanced. - eggs - osmotic burst of cells - amoeba sisters osmosisSolution QuestionsIf a cell at 1% solute, is placed in a solution that is 1.5% solute, what will happen to the cell? Why?The cell will shrink because water will move out of it to balance the salt concetration.If a cell is isotonic in 0.5% solute, what will happen when it’s placed in a 0.1% solute solution?The cell will swell. Water will move into it.A cell is isotonic in a 0.9% solute solution. If this cell is placed in a solution and it swells and bursts, what % solute could the solution have been?Anywhere between 0-0.4%If two cells are placed in a solution and one shrinks, while the other doesn’t, how is this possible? Explain.The cells probably had different concentrations of solutes and so reacted differently to the solution.3. Facilitated diffusion: diffusion with the help of a protein channel. Substances still move from an area of high concentration to low concentration. The substance attaches to the protein which assists its movement into or out of the cell. Each channel protein would be specific to a certain molecule.Larger molecules and some polar molecules are transported this way. transport Requires the use of energy (ATP) to move molecules across the membrane, against the concentration gradient. Think of how much energy it takes to go uphill. There are many forms of active transport:Ion pumps: Carrier proteins in the plasma membrane act as pumps to move ions against the concentration gradient. These are special pumps designed specifically for the ions that they carry. Some pumps will carry one type of ion and other pumps may carry two types like the sodium potassium pump shown below. These pumps are crucial in the functioning of the nervous system but play a role in many different body systems.: To expel or remove bulk substances from the cell. Vesicles , containing the materials, fuse with the plasma membrane and expel contents into interstitial fluid. The plasma membrane will adjust to fit these new phospholipids. Peripheral proteins are often involved here. This process could be used in expelling wastes or moving substances like proteins from one cell to another. : To bring bulk material from outside of cell into the cell from the interstitial fluid, will be engulfed by the plasma membrane. The membrane will pinch off to form a vesicle that will enter the cell. Peripheral proteins are often involved here. Two types of endocytosisa. Pinocytosis: ingestion of fluidb. Phagocytosis: ingestion of solidsTransport QuestionsWhat does concentration gradient have to do with transport?The concentration gradient will help determine how substances will move, either passively or actively. If there is no concentration gradient, passive transport will not occur and so energy will be needed to move those substances. A high concentration gradient will help move molecules through diffusion.What is the main difference between active and passive transport?Active transport requires energy to move substances from LOW to HIGH concentration and passive transport does not require energy because it moves substances from HIGH to LOW concentration. What are three types of passive transport? How are they different?Diffusion, Osmosis, Facilitated DiffusionIn all three types we see movement from high to low concentration but diffusion is of various molecules, osmosis is of water only and facilitated diffusion used a channel protein to move only large non-polar or polar molecules.What are the three types of active transport? How do they differ?Ion pumps – moves ions across cell membranes with a carrier proteinEndocytosis – movement of bulk materials into the cell with the help of the cell membrane and phosphplipids. Two types – pinocytosis and phagocytosisExocytosis – removal of bulk materials from the cell with the help of the plasma membrane and phospholipids.Cellular Respiration and ATP (energy molecule)The cell needs a lot of energy to keep our bodies alive and moving.Cellular respiration is a process in which the energy stored in the chemical bonds of glucose is transferred to ATP. This occurs at the mitochondria through a three-part process. This is the overall chemical reaction for cellular respiration.C6H12O6 + 6O2 ------ 6CO2 + 6H2O + energy (36 ATP)Glucose (food we eat) + oxygen (air we breathe) ------- carbon dioxide + water + energyThe energy (ATP) is then used to power the reactions in our body using the method described below.Without sugar or oxygen the body cannot produce adequate energy to fuel metabolic reactions, which may be needed to move muscles or fire off messages from the brain.How does ATP provide energy for the cell? Metabolism is the sum of all the chemical reactions that take place in a living organism. These reactions manage the material and energy resources of the cell. When breaking down molecules it is called a catabolic reaction. When creating a molecule it is called anabolic. The energy that is acquired through breakdown of food and during cellular respiration can be used right away or stored for a later time. We can’t possibly use all the energy we obtain at one time so we need some form to store it. The molecule ATP – adenosine triphosphate is the universal energy storage carrier for the cell. The “tri” represents the 3 phosphate groups. The energy is stored in the chemical bonds between the three phosphate groups. In order to release this energy, we must break these bonds. In the presence of the enzyme ATPase, the ATP molecule loses a phosphate. This new molecule is called ADP – adenosine diphosphate. The energy released by this process can fuel chemical reactions within the cell. The free phosphate can be refused again to regenerate ADP into ATP. Fig 1 Fig 2You can think of ATP as a rechargeable battery. Once the energy is used up and it converts to ADP, it can be recharged and used again. This saves the body energy by not having to create and entire ATP molecule. - how cells obtain energy amoeba sisters - song ATP - how cells use ATPAging why do we age why we age and how can we stop it seniors with toddlers ................
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