Chapter 4-The Business of Life - Mr. Steckle's SciencePage



Chapter 4-The Business of Life

All living things use energy to maintain themselves and grow. The accomplish this through a vast number of reactions called ______________________.

Water is the ____________________, which means it can dissolve more (but not all) different substances than any other liquid. That comes in handy since most living things are 2/3 or more water.

Life requires an enormous number of chemicals besides water. Most of these are ______________________, molecules that contain carbon, hydrogen and usually oxygen. Organic compounds are high in energy and if left alone they will breakdown and release the energy that went into making them. Organisms have learned how control this breakdown and harness the energy that is released.

Carbohydrates

_____________________ are one of the four major groups of organic compounds. Simple sugars like ____________ are the basic unit and these could be linked together to form more complex molecules.

C6H12O6

________________ and other complex carbohydrates consist of longer chains of simple sugars. Complex carbohydrates are used for ___________________ as well as for _______________ purposes.

____________ is the main ingredient in plant and wood fibers and some animals use a modified form called ____________ as a skeletal material.

Proteins

____________ are composed of chains of simple molecules. A protein sub unit is called an amino acid, which contains an atom of ____________ as well as carbon, hydrogen and oxygen. Amino acids are held together by _____________bonds.

GLYCINE ALANINE

Some proteins are ___________________ which act as chemical messengers to help the body work together.

Lipids

Fats, oils and waxes are examples of __________, which are primarily used for energy storage. Lipids ________________, so many birds have a coating of oil to keep their feathers dry while other animal use a layer of wax to keep in the moisture during times of low tide or exposure to the air. Lipids are also useful to keep in heat and create ____________ because of their buoyancy.

Nucleic Acids

Nucleic acids store the basic genetic information inherited from the parents. The subunits are called _________________. One of the most important nucleic acids is _______.

The Fuel of Life

Photosynthesis-Making the Fuel

Almost all living things ultimately get their energy from the sun. _____________________ captures the sun’s energy and turns it into simple sugars, which plants and many other organisms ultimately use for food.

6 CO2 + 12 H2O + Light Energy C6H12O6 + 6 O2 + 6 H2O

Photosynthesis begins when ______________________, a photosynthetic pigment absorbs the sunlight. This is usually the bright green coloring of plants, but other colors do exist.

Organisms that are capable of obtaining energy from the sun without eating are called ___________________. Organisms that need to obtain food are called ___________________.

Primary Production

When autotrophs produce more organic material than they use, the net increase is called __________________. The autotrophs will use this extra energy to grow, which means more food for animals and other heterotrophs. Organisms that do this are sometimes called _______________.

The Importance of Nutrients

Carbon dioxide, water and sunlight are needed to make simple sugars, but it is ________________ that help convert the sugars into other organic compounds. In primary producers, nitrogen and phosphorus are needed to make nucleic acids. _______________ NO3 and _______________ PO4 are commonly used.

Living Machinery----Cells and Organelles

The basic unit of life is the ______. The ______________ contains the cytoplasm and other membrane bound structures called ____________.

Prokaryotic Cells

They are the simplest and smallest types of cells because they have no membrane bound organelles. Bacteria are prokaryotes. They have a cell wall outside of the cell membrane and inside is the cytoplasm as well as DNA, and if the bacteria is photosynthetic, the photosynthetic pigment will lay in the folds of the cell membrane.

Eukaryotic Cells

The organelles are membrane bound and do special jobs. The _________ contains the chromosomes that carry the cells DNA. The nucleus is the headquarters of the cell.

The eukaryotic cell may have a ___________. If they are all short and numerous they are called ________. The cell will use either of these to move or swim, or to push food along to the mouth.

The cell may also have a complex internal framework called a cytoskeleton that supports it to move and change shape.

Levels of Organization

The cell is a self contained unit that can carry out all of the functions necessary for life. Some organisms get by on only one cell, these are called unicellular. Most eukaryotic organisms are multicellular. The levels of organization go from cellular to the tissue level to the organ level to the organ system level.

Complex

Simple

Interactions Among Individuals

A ______________ is a group of organisms of the same kind or species that lives in one place. Populations of different species are called a _______________. A community or group of communities together with the physical environment make up an _________________.

Challenges of Life in the Sea

__________________ organisms-drift in the water

__________________ organisms-live on the bottom

__________________-organisms that swim

Dissolved Material in Seawater

__________________ is the movement of ions to move from areas of high concentration to areas of low concentration. The salt in the water will move in or out of the concentrations are different. In order to prevent this in cells the cell has a cell membrane. The cell membrane uses _____________________.

The next problem is that if the ions are prevented, the water will move to level out the concentrations. The diffusion of water across a selectively permeable membrane is known as ______________.

Regulation of Salt and Water Balance

Marine organisms have adapted to life in the sea. ________________ have the ability to change their internal concentrations of salt to match the salt content of the area. In the ocean they do fine because the salinity doesn’t change much. If you put these animals in fresh water, they will swell up because the water will diffuse in to try to match the surrounding concentration.

Other animals are _____________________, they regulate their internal composition as long as the total concentration of the ions remain the same. For example, sharks use urea in their blood to regulate.

Most osmoregulators have internal concentrations lower than the surrounding seawater so these fish lose water to the outside. To replace the water they drink sea water and excrete the salt in the urine or out by the gills.

Fresh water fish have the opposite problem, so they do not drink and excrete a large amount of dilute urine.

Some other marine birds and reptiles have special glands to get rid of the extra salt called “salty tears”.

Temperature

Temperature can have a huge affect of how fish operate. Fish are called ______________ which means their body temperature changes with the surroundings. Larger fish can overcome this by using their muscles to create heat. This slows the bodies cooling rate.

Mammals are called _______________, they create heat produced by muscle activity.

Asexual Reproduction

This is the reproduction without the need for a partner. The offspring of the parent are clones. Most of the time this is for single celled organisms. Some multicellular animals like sea anemones will split in half into two smaller anemones. This is called fission. Other organisms will use ____________, which means that the parent will develop small growths that will develop into separate individuals.

Sexual Reproduction

Sexual reproduction requires two separate cells called gametes. Sperm from the testes meets the egg from the ovaries and a new individual is born.

Reproductive Strategies

Some organisms will produce millions of eggs in the hope that a few will survive with little parental involvement. Another strategy is to have a few offspring but invest a lot of time in their survival. Female lays eggs and the male fertilizes them outside of the body.

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