(III) ENERGY and ENZYMES



Metabolic Processes

T.A. Blakelock High School

Grade 12 University Preparation Biology

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Student:______________________ Date:___________________ Teacher:______________________ Room:__________________ Period:_________

UNIT II METABOLIC PROCESSES

WAR M UP- Pages 108-109

Part I ENERGY and ENZYMES

A. ENERGY

1. Chemical potential energy – energy stored in _________________________________

2. transition state – a temporary condition in which bonds are______________________________

3. activation energy – the energy that must be ____________ to get to the ________________ state

[all molecules that exist are stable and so to change them we must add energy]

4. storing free energy

- in a cell energy can be stored as ATP and later re-used

_____ kJ/mol + ADP + Pi ________ + _________

ATP + H2O ________ + __________ + _____________

5. Phosphate

___________ phosphate ______________ phosphate

Pi – P

6. oxidation and reduction

a. oxidation is the ____________ of electrons and their energy

b. reduction is the ________________ of electrons and their energy

c. often a series of oxidation and reduction reactions allows a cell to move __________

between molecules and eventually use it to produce _________________

7. Transferring energy

a. Energy can be transferred by moving ____________ or ___________ between molecules.

b. If a molecule ____________________ either phosphates or electrons, it gains energy

c. All chemical reactions require the _________________ of energy to start the reaction

d. This ___________________ energy may come from phosphate or from electrons

B. ENZYMES

1. enzymes are protein ___________ that ____________ the activation energy in a biological reaction

2. the ACTIVATION energy is the energy that must be ___________ to initiate or start a reaction

3. there are two types of enzymes based on energy: _______________ & ___________________

a. EXERGONIC REACTION – a reaction that has a net _____________ of energy

b. ENDERGONIC REACTION – a reaction that requires a net____________ of energy

c. the presence of an enzyme does __________________ affect the free energy level

of the ___________________ or the ______________________

d. enzymes only reduce the activation energy required to __________________ the reaction

4. How enzymes work

________________ molecule that the enzyme acts on

________________ site

[shape is specific to one _____________ molecule only]

enzyme - _________________ complex

[note that the _____________ has changed shape]

this change is to allow for the ______________ or

breaking of _____________ in the substrate

________________

__________ site

note that enzyme has returned to its

original _______________

__________________ has entered the ______________ site and changed the shape of the

___________________ site thus shutting down the enzyme activity

Not shown is the situation when an _________________________ enters the _______________ site

and causes the ________________ site to change so as to enhance the activity of the enzyme

5. Types of enzymes

a. ISOMERASE – an enzyme that changes the ________________________ of atoms in a molecule

b. DE HYDROGENASE – an enzyme that removes hydrogen along with ______________

and their____________________

c. DEHYDRASE – an enzyme that removes ________

d. DECARBOXYLASE – an enzyme that removes _______________________

e. PHOSPHORYLASE – an enzyme that makes ____________ or uses___________ for a reaction

[also called kinase]

6. High energy compounds

-all energy in a cell ultimately comes from the _______________

-that energy must be converted to __________ ___________ compounds in order to be useful

-___________ and _____________ are the two high energy compounds used in photosynthesis

-________ is the energy currency in the cell

- ___________ actually contains more energy than ATP,

but this energy is _________directly available to the cell

3. Making High Energy Compounds

a. ADP + ______ + ______________ ( ATP

NADP+ + ______ + ______________ ( NADPH + H+

b. are both _______________________ reactions as _________________ is added

because a molecule is being built up, these are called _________________ reactions

Part II PHOTOSYNTHESIS

A. Introduction

1. Location: ____________________ (in plants and algae) or

________________ in cell membrane (in photosynthetic prokaryotes, cyanobacteria)

2. Stages in photosynthesis:

Stage 1. capturing light energy; occurs in ____________________ membrane

Stage 2. light energy makes ATP + ___________________; occurs in thylakoid membrane

Stage 3. using ATP + NADPH + H+ to _______________ organic compounds (glucose)

from CO2 (carbon fixation); process called ____________; occurs in __________

3. Overall process:

6CO2 + ______ + light energy chlorophyll C6H12O6 + ______ + _______

the carbon + oxygen from CO2 and the H from ____________ produce the glucose

the oxygen from ___________ is released as oxygen gas

4. Light energy:

light energy travels in wave packets called ______________

visible light has a wavelength of 380 nm (_______) to 750 nm (___________) (ROYGBIV)

short wavelengths [violet] is _____________ energy

long wavelengths [red] is _______________ energy

clusters of photosynthetic pigments embedded in the ____________________________ absorb photons of a particular λ

energy is transferred to ADP + Pi ---> __________

NADP+ + 2H (from H2O) ---> ____________________ + _____________

5. Chlorophyll:

-pigment molecule (see pg. 139) has 2 parts:

long ____________________________ tail; (hydrophobic)

a ring of C, N, and lots of ______________________, Mg trapped in middle;

-____________________ (primary light absorbing pigment in all photosynthetic organisms)

and _______________________ absorb photons of blue-violet λ and red-orange λ

-green wavelength are _______________ (that is why leaves appear green)

and green light is _____________ so leaves look ____________ from underneath

-in fall, __________________ is no longer produced and is broken down,

other pigments (e.g. red or yellow) show through and leaves ____________________

B. Light Reactions

1. Photoexcitation

electrons are normally stable in their _________________, the lowest possible energy level

when a photon strikes a chlorophyll molecule, the e- have ______________ added to them

and are in a state of ______________________

an excited e- has more _________________ than one in a ground state,

but it will _________________ to the ground state in 1 billionth of a second

when the e- returns to the ground state it ___________________ energy (heat + light)

instead of the e- from chlorophyll releasing heat + light, they are ___________________

by a primary electron ____________ (chlorophyll is oxidized, e- acceptor is reduced)

2. Photosystems

photosystems = a group of pigments that work together to ________________ light

the __________________________ consists of several hundred pigment molecules that

capture light of different ________________ and pass energy to the reaction center

the ____________________________ is a chlorophyll a pigment that takes all the energy

and uses it to _________________ an electron

the excited e- is _________________________ to an e- acceptor

(chlorophyll is oxidized, primary e- acceptor is reduced)

3. Sources of electrons:

a) bacteria:

______________________ contains chlorophyll P700 (max. absorption at 700 nm λ)

the photosystem I does not have enough energy to break _____________,

however it does have enough energy to break _________________

but H2S is rare; only found in _______________________________

6CO2 + _________ + light energy ---> ___________ + 6H2O + _______

b) algae and plants

______________________ contains chlorophyll P680 (max. absorption at 680 nm λ)

photosystem II does have enough energy to break ____________

______________ are then passed to photosystem I

________ + 12H2O + light energy ---> __________ + 6H2O + ________

c) photosystem I and II are used to produce __________ + __________________

4. Photolysis (the breaking of water by sunlight)

the ___________________ (in the thylakoid space) uses energy from light to split H2O

___________ are given to photosystem II

_____________ are released in the thylakoid space and create an electrochemical gradient

_________ leaves the chloroplast as waste

5. Electron Transport System

a) Occurs in the _______________________________.

b) Photon strikes photosystem II and ___________________ of chlorophyll P680, _____ passed to

electron _____________________ called Plastoquinone (PQ).

c) ______ from _____________________ replace the missing ______ from Chlorophyll P680.

d) PQ takes _________ from photosystem II and ____________ with them to the b6f Complex.

e) b6f Complex takes ____________ and passes them on to plastocyanin which allows _________ to pass

from the stroma into the thylakoid space.

f) This creates an __________________________________________ gradient.

g) Pc takes 2e- and moves with them to ____________________ .

(these replace 2e- lost when photosystem I was struck by a photon)

h) Photosystem I transfers 2 e- to ferrodoxin (Fd) an electron ______________ .

i) Fd transfers 2e- to ______________ reductase.

j) _______________ reductase passes on the 2 e- to NADP+

k) (NADP+ + ___ + ____ ( NADPH + H+)

6. Types of Electron Transport Systems

a) non-cyclic _______________________ (aka non-cyclic electron flow)

normal process as described in ______________

involves both______ and _______ and transfers e- from H2O to _______ to produce

1 NADPH + H+ and 2 ATP needed to make __________

H2O + photons + 2ADP + 2Pi + NADP+ ---> _______ + _________ + ___________

but demand for ATP and NADPH + H+ is not always in a _________

b) cyclic _____________________ (or cyclic electron flow)

electrons from P700 are excited but eventually _________________ (H2O and NADP+ are not involved)

P700 --> ________ --> b6-f complex --> protein C --> P700

b6-f complex pumps _______________ across the thylakoid membrane,

creating an electrochemical _____________ which is used to make ATP

C. The Calvin cycle

occurs in the _____________

1. Phase 1: carbon fixation

a CO2 is added to a 5-C ribulose biphosphate ( ________ ) to form a 6-carbon intermediate

this unstable intermediate _________________ splits into

two 3-carbon molecules of 3-phosphoglycerate ( __________ )

enzyme involved = ribulose biphosphate carboxylase ( ______________ ),

a very large and slow-working _____________________

this process happens ________________ to make one glucose,

6 x (5-carbon) ___________ + 6CO2 ---> 12 x (3-carbon) _________

this process is called ______ photosynthesis because

the first product of fixation is a ______________ molecule

2. Phase 2: reduction reactions

a series of reactions that are essentially the reverse of _________________

_________ is phosphorylated to biphosphoglycerate (BPG) using _________

_________ is reduced to glyceraldehyde-3-phosphate (G3P) by _____________________

1 molecule of _________ leaves the cycle for every 5 molecules of G3P that go on

2 molecules of G3P will combine to make __________________

3. Phase 3: RuBP regeneration

_____ molecules of 3-C ________ are converted into ____molecules of 5-C _________

we start with ____ phosphates (1 per G3P) and must end with ___ (2 per RuBP)

in the process _______ are removed and ____________ are consumed

____________ must be added for the H and OH groups to add to the molecules

4. Overall equation

6CO2 + 18ATP + 12(NADPH + H+) + 10H2O + 6RuBP

---> _______ + _______ + ________ + _________ + _________

6 RuBP are both reactants and products in the reaction

5. Fate of G3P

chloroplast G3P glucose ____________

glucose

cytoplasm

__________ cellular ________________

__________ (cell walls)

transported

to other parts of ______________

plant (translocation) (storage)

Part II CELLULAR RESPIRATION A. OVERVIEW

1. Purpose

to convert energy trapped within ______________

to energy available to do work in cell in the form of _____

2. High energy compounds

-although the ultimate goal is to produce _______________

-high energy intermediates such as ____________ & _________ may be produced along the way

-NADH + H+ and FADH2 actually contain ________________ energy than ATP,

but this energy is ____________ directly available to the cell

|LOW energy compounds |HIGH energy compounds |

| | |

| | |

| | |

| | |

3. Making High Energy Compounds

a. ADP + ______ + ______________ ( ATP

NAD+ + ______ + ______________ ( NADH + H+

FAD + ______ + ______________ ( FADH2

are all _______________________ reactions as _________________ is added

because a molecule is being built up, these are called _________________ reactions

b. in order to get the ___________________ to power these reactions,

the cell must couple them to ________________________ reactions

c. ___________________ [breaking down] steps are generally _______________________

d. cellular respiration is a series of ____________________ steps

involving the breaking of ___________________ compounds

coupled to a series of ___________________ steps

involving building _____________________________ compounds

B. GLYCOLYSIS

1. Which cells? _________ cells must do cellular respiration to survive

2. Where in the cell?

cellular respiration starts in the ______________

and is completed in the _________________ [if present]

3. Purpose

a. to convert the energy stored in _______________ with-in the glucose molecule

to more readily ____________________ energy stored in bonds within ATP

b. ATP will only be made ________________________ if there is the right amount of energy

____________________ when bonds are broken

c. if too ______________ energy is released to make an ATP, that energy is simply__________

d. if __________________ energy is released than needed to make one ATP

then an ______________________ or other very high energy product will be made

this will later be ____________________ into more than one ATP

4. Summary

a. _____________ (C6H12O6) is broken down into two molecules of _____________ (C3H4O3)

b. in order to break glucose, it must first be destabilized by the addition of ______________

c. once the destabilized molecule breaks in half, it releases enough energy to replace the

______________ and to make additional _____________

d. in addition to the ATP, the high energy compound, 2 _________________ are also produced

5. Equation

glucose + _________ + ________ + __________ + ________ (

____________ + _________ + _________ + ___________ + ___________

6. Energy

a. each _________________ has 2870 kJ/mol free energy in it

b. it requires _____________ kJ/mol to make 1 ATP

2870 kJ/mol

c. therefore each glucose can theoretically make 31 kJ/mol = __________ ATP

d. so far, we have made a NET of 2 ATP 2 / ________ = ________% efficiency

e.

7. Next step

there is still lots of energy left in ______________ that the cell can use to make

more __________

C. FATE OF PYRUVATE

1. Why cell gets rid of pyruvate

a. the process of _____________ causes cell to run out of ______________ so glycolysis stops

b. as all cells must do glycolysis _______________________

therefore, they must use ______________ to regenerate ________________ for cell

c. there is a lot of __________ trapped in pyruvate and ideally cells would access that energy,

but that is only possible if a cell has a _________________ and access to ____________

2. What is CoASH

a. coenzyme-A is a _____________________ that helps enzymes hold and modify molecules

b. coenzyme-A has a sulphur and hydrogen __________________ group [designated as _______]

c. the result is that we use the code ____________ for an ___________________ coenzyme-A

and the code ___________ when coenzyme-A is ______________ to another molecule

3. Three pathways for pyruvate

a. ethanol fermentation -occurs in _____________ or ____________ cells

pyruvate + ________ + _____ ________ + _________ + ___________

b. lactic acid fermentation - occurs in _____________ cells in the temporary absence of _________

pyruvate + _________________ ___________ + ______________

both fermentation steps above do NOT directly create any ________________________ compounds

but they do both release _________ to allow the cell to continue _____________________

c. oxidation of pyruvate - occurs in the __________________ in the presence of ________

pyruvate + NAD+ + ___________ __________ + __________ + ___________

D. Krebs cycle

1. Krebs cycle allows the cell to get more energy out of the _______________ product of the oxidation of pyruvate

2. occurs in the ________________ of the ___________________

3. only occurs if __________________ is present

4. details for “Kreb’s cycle” shown on next page

5. equation:

acetyl-CoA + 3 __________ + _____________ + H20 + ADP + Pi

2 _____________ + __ NADH + H+ + FADH2 + ________ + _____

E. Summary – so far

F. Electron Transport Chain [ETC]

1. Overview

a this occurs in the __________________ of the ___________________

b. a series of _______________________________ reactions that converts the stored energy

in __________________ or ________________ indirectly into ___________

c. the process involves moving _________________ between proteins within the membrane

and this results in ____________________ movement across the membrane

2. Accessing the NADH+H+ and FADH2

Kreb’s cycle occurs in mitochondrial matrix ( __ x ___ NADH+H+

__ x ___ FADH2

oxidation of pyruvate occurs in mitochondria matrix( __ x ___ NADH+H+

glycolysis occurs in the cytoplasm( __ x ___ NADH+H+

3. Getting the energy into the mitochondria from the cytoplasm

NADH+H+ from the cytoplasm can not pass through the _______________ membrane

and therefore can not directly enter the ____________

however, the __________________________ in NADH+H+ can be passed across the

membrane with the ______________ to a molecule of FADH2

4. “ETC” page showing details

5. Proteins

a. NADH dehydrogenase – accepts 2 ______________ from NADH +H+ and passes them on

- 2 ____ [protons] follow the electrons & ______________________the membrane

b. protein Q - accepts 2 electrons from NADH dehydrogenase

or _____________________ and passes them on

c. cytochrome b-c1 complex - accepts 2 electrons from _______________ and passes them on

- 2 _____ [protons] follow the electrons & pass through the __________________

d. cytochrome c - accepts 2 __________ from cytochrome b-c1 complex and passes them on

e. cytochrome oxidase complex - - accepts 2 electrons from cytochrome c

& passes them on to _______________________

- 2 ______ follow the ____________ & pass through the membrane

ELECTRON TRANSPORT CHAIN

1 – NADH dehydrogenase 2 – protein Q 3 – cytochrome b-c1

4 – cytochrome C 5 – cytochrome oxidase 6 – ATP synthase

6. tally of H+ across the membrane

a. for every NADH+H+ ( __________ of H+ are pumped into the intermembrane space

b. for every FADH2 ( __________ of H+ are pumped into the intermembrane space

7. ATP synthetase [not technically part of the ETC]

a. there are more H+ in the __________________________ than in the matrix

b. the H+ try to move down a concentration ___________________ back across the membrane

c. the H+ can __________________ pass through the phospholipid membrane directly

d. the enzyme ____________________________ allows the H+ to pass through it

e. as the H+ pass through the ATP synthetase they __________________________________

and when it returns to its normal shape it is able to add ______ + _______ ( _________

8. Summary 9. Overall summary

pg 108 Fig. 22 pg 110

G. RELATED PATHWAYS

1. Carbohydrates

- cells first choice for ‘food’ for _____________

broken down by simple __________ cellular respiration

2. Proteins

H

-proteins breakdown into___________________ H2N--C--COOH

R

-____________________ removes the amino [NH2] group

-the remainder enters the energy cycle at various points, eg:

leucine (______________; alanine ( _____________; proline ( into _____________

3. Lipids

- ____________________ ( glycerol + 3 fatty acids

- _________________ ( ( 3-phosphoglycerate [into __________________]

- 3 _______________ ( beta-oxidation

beta-oxidation

- most fatty acids are __________ carbons long

O

H H H H H H H H H H H H H H H H H //

H – C – C – C – C – C – C – C – C – C – C – C – C – C – C – C – C – C – C – OH

H H H H H H H H H H H H H H H H H

how many carbons in acetyl-CoA ? _______________

so how many times do we have to cut the 18 carbon fatty acid? _____________

To calculate the energy released by lipid breakdown, there are two steps.

Step One: ______________ step that converts a long chain of carbons into a series of acetyl-CoA

The oxidation of fatty acids into acetyl-CoA molecules requires the _______________ of bonds,

always one __________________ bond that the number of acetyl-CoA.

To break bonds, we must add ______________ and _________________.

When these fatty acid bonds are broken, ____ FADH2 and ____ [NADH + H+] are produced.

Given these steps, the beta-oxidation of an 18 carbon fatty acid is shown below.

____ carbon fatty acid + ____ CoASH + _____ATP + _____FAD + _____ NAD+ + _____H2O (

9 ____________ + 8[______+ ______] + 8_________ + 8[________ + ____]

Step two: the breakdown of the acetyl-CoA through the normal _____________ cycle.

One turn through Kreb’s cycle produces ______ ATP: _________ FADH2: ____[NADH + H+].

To determine the total number of high energy compounds produced this way, we must multiply these

_____________ numbers by the ________________ of acetyl-CoA’s.

So to combine both we use the chart below

|1 acetyl-CoA |9 acetyl-CoA |OXIDATION |NET |ATP |3 X GLUCOSE |

|__ ATP |___ ATP |___ ATP |___ ATP |____ ATP | |

|__ NADH+ H+ |___ NADH+ H+ |___ NADH+ H+ |___ NADH+ H+ |____ ATP | |

|__ FADH2 |___ FADH2 |___ FADH2 |___ FADH2 |____ ATP |______ ATP |

| | | |TOTAL |____ ATP |______ ATP |

This shows lipids store MORE energy than carbohydrates

_____ ATP / ______ ATP = _______ % more energy per carbon.

HW do this calculation for 12 carbons and for 20 carbons from the Assignment Package

-----------------------

2100kJ

2870 kJ

OH

2x PYRUVATE

HC=O

HCOH

H2C—O—P

glycerol phosphate shuttle protein

_______________________________________

________

______ _________

______

_________ ___________________ _________________

oxidation of pyruvate Kreb’s cycle

glucose glycolysis

oxidation of pyruvate Kreb’s cycle

_________

HC=O

HCOH

H2C—O—P

free

energy

GLYCOLYSIS: Part 2 – Rearranging the 3-carbon molecule

free

energy

H2COH

C=O

H2C—O—P

GLYCOLYSIS: Part 1 – Breaking the glucose [Textbook pg 98]

GLUCOSE

H

OH

H

OH

OH

OH

C

CH2OH

COOH

C—O—P

II

CH2

COOH

HC—O—P

HOCH2

COOH

HOCH

H2C—O—P

O=C—O—P

HOCH

H2C—O—P

HC=O

HCOH

H2C—O—P

COOH

C=O

CH3

CALVIN CYCLE

COOH

l

HCOH

l

CH3

S-CoA

l

C=O

l

CH3

H2C-OH

l

CH3

PYRUVATE

FATE OF PYRUVATE

[pic]

OH

l

C=O

l

C=O

l

CH3

1

2

3

4

5

6

___ Pi

___ H2O

___ x ADP

___ x ATP

____ x P--C-C-C-C-C—P

ribulose biphosphate

____ x C-C-C—P

[G-3-P]

glucose

__ x C-C-C—P

[G-3-P]

____ x ________________________________

[G-3-P]

____ x _________________________

[3-PGA]

z ( Z protein 4 ( plastocyanin [PC] 8 ( ATP synthetase

1 ( photosystem II (P680) 5 ( photosystem I (P700)

2 ( plastoquinoe [protein Q] 6 ( ferridoxin [Fd]

3 ( b6-F complex 7 ( NADP reductase

6

z

4

7

5

3

2

1

8

thylakoid space

stroma

KREBS CYCLE

where

Acetyl-CoA

CH3

C=O

S-CoA

COOH

HOCH

CH2

COOH

COOH

CH

ll

HC

COOH

COOH

CH2

CH2

COOH

COOH

CH2

CH2

C=O

S – CoA

COOH

CH2

CH2

C=0

COOH

COOH

CH2

HC – COOH

HOCH

COOH

COOH

O=C

CH2

COOH

COOH

CH2

HOC – COOH

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COOH

+

enzyme _________ activation energy

activation energy

_________ enzyme

activation energy

____________with enzyme

____________ energy without enzyme

oxaloacetate

malate

fumarate

succinate

succinyl-CoA

alpha-ketoglutarate

isocitate

citrate

COOH

C=O

CH3

COOH

C—O—P

II

CH2

COOH

HC—O—P

HOCH2

COOH

HOCH

H2C—O—P

O=C—O—P

HOCH

H2C—O—P

2x

G

3

P

free energy

HO

OH

HO

OH

OH

OH

H

H

H

H

H

O

C

C

C

C

H

H

H

H

H

O

C

C

C

C

C

CH2O – P

OH

H

H

O

P – OCH2

C

C

C

C

H2 COH

OH

OH

H

H

O

P – OCH2

C

C

C

C

H2 CO – P

2

x

P

E

P

2x

2

P

G

2x

3

P

G

2x

1,

3BPG

D

H

A

P

+

G

3

P

F

1,

6

B

P

F

6

P

G

6

P

G

L

U

C

O

S

E

Relative energy levels in glycolysis intermediates

___________________

___________________

[1,3-BPG]

COOH

HOCH

H2C—O—P

O=C—O—P

HOCH

H2C—O—P

HC=O

HCOH

H2C—O—P

happens in all plants when ______________ is needed

the process produces only ATP and not ____________

one of the proteins in the thylakoid membrane ________

in order for the cycle to flow

photosystem I (P700) involved, ______________

photosystem II (P680)

6

3

2

1

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