Ch 8 Cellular Respiration Review

bio review

All cells metabolize _______ for ________.

glucose; energy

Where does glycolysis occur in a cell?

cytoplasm

What does glycolysis break down and into what?

6-C glucose into 2 3-C pyruvate molecules

If oxygen is absent, pyruvate is converted by _________ in the cytoplasm to _________ or ________.

fermentation; lactate; ethanol and carbon dioxide

In fermentation, pyruvate is converted into ______ in animals.

lactate

In fermentation, pyruvate is converted into ______ in yeast and some plants.

ethanol and carbon dioxide

If oxygen is present, pyruvate is completely broken down into ________ and _________ in the ____________(organelle), generating amounts of ______.

CO2; H2O; mitochondria; ATP

Each metabolic reaction is catalyzed by a specific _________.

enzyme

_________ and _________ accept electrons and carry them to the ________.

NAD+; FAD+; ETC

NAD and FAD are ___________ continuously.

recycled

In the glucose activation phase, glucose is converted to __________, which is ______________(structure).

fructose-biphosphate; 6-C glucose with 2 phosphates attached

Glucose activation costs _____ _____.(how many and what)

2 ATP

In the energy harvesting steps of glycolysis, ___________ splits into ____ molecules of _______.

fructose-biphosphate; 2; G3P

In the energy harvesting steps of glycolysis, each G3P molecule goes through a series of steps to be converted into ___________.

pyruvate

The energy harvesting steps of glycolysis produce ___ ______ and ___ _____. (how many and what)

2 NADH; 4 ATP

Glycolysis produces a net ___ _____ and ___ _____ for each glucose molecule. (how many and what)

2 ATP; 2 NADH

The processes of cellular respiration that occur in the mitochondria are ____________, __________, and ___________.

transition reaction; Citric Acid Cycle; Electron Transport System

What is the Citric Acid Cycle also called?

Kreb’s Cycle

In the mitochondria, ___________ is completely broken down into _______ and _______.

pyruvate; CO2; water

The mitochondria has a ________ membrane with a _________ space between the ________ and _________ membrane.

double; intermediate; outer; inner

What are cristae?

inner folds of the mitochondria that jut into the matrix

What is the matrix?

innermost component of mitochondria filled with jellylike fluid

Which processes occur in the matrix?

transition reaction and Citric Acid Cycle

Which process occurs in the cristae?

Electron transport system

What happens in the transition reaction?

Pyruvate reacts with a molecule of coenzyme A to produce acetyl-CoA, one molecule of CO2, and one molecule of NADH.

How many times does the transition reaction occur in one cycle of cellular respiration? Why?

2; once for each molecule of pyruvate

What is the transition reaction also called?

Preparatory reaction

Where does the Kreb’s Cycle occur?

matrix

What are the steps of the Kreb’s Cycle?

1. acetyl (C2) group joins a C4 molecule making a C6 molecule called citrate

2. During the cycle the 2 acetyl C’s are oxidized to form CO2

3. During cycle oxidation, 3 NAD+ molecules and one FAD+ molecule are reduced

• NAD+ accepts 2 electrons and one H, producing NADH

• FAD+ accepts 2 electrons and two H, producing FADH2

How many ATPs are produced in the Kreb’s Cycle?

one

How many times does the Kreb’s Cycle turn per original glucose molecule?

twice

At the end of the Kreb’s Cycle, all 6C’s are now _____.

CO2

Where is the electron transport system located?

in the cristae

What is the electron transport system?

a series of carriers (some cytochrome molecules) that pass electrons from one to another

In the electron transport system, _________ serves the terminal electron acceptor and combines with ___ to form _____ through the process of _______________.

oxygen; H; water; oxidative phosphorylation

When NADH delivers electrons to the ETS, how many ATP are formed?

3

When FADH₂ delivers electrons to the ETS, how many ATP are formed?

2

In the ETS, protein complexes pump H+ ions from the _______ into the _____________. This creates a _________ across _________.

matrix; intermembrane space; gradient; cristae

How is ATP produced by the gradient in the ETS?

ATP synthase complexes allow H⁺ ions to flow back into the matrix down the gradient, generating ATP in a process called chemiosmosis.

What happens in substrate-level phosphorylation?

Direct transfer of a phosphate group from a substrate molecule to ADP, forming ATP

What process(es) include(s) substrate-level phosphorylation?

glycolysis and Kreb’s Cycle

What process(es) include(s) oxidative phosphorylation?

Electron Transport System

What are the outputs of the Citric Acid Cycle?

4 CO2, 6 NADH, 2 FADH₂, 2 ATP

What are the inputs of the Citric Acid Cycle?

2 acetyl groups, 6 NAD+, 2 FAD+, 2 ADP+ + 2 P+

How many ATP molecules are produced in glycolysis?

2

How many ATP molecules are produced in the Citric Acid Cycle?

2

How many total ATP molecules are produced outside of the ETS?

4

The most ATP is produced through the ________________.

Electron Transport System

In cellular respiration, from one molecule of glucose, ___ NADH(___ in mitochondria, ___ from cytoplasm) and ___ FADH₂ are produced in total.

10 NADH; 8; 2; 2 FADH₂

What is oxidative phosphorylation?

ATP formation powered by the Electron Transport System (ETS) and chemiosmosis using energy from NADH and FADH₂

For each NADH made in the mitochondria that enters the Electron Transport System, ___ ATP are made, resulting in ___ ATP total.

3; 24

For each FADH2 from the Kreb’s Cycle that enters the Electron Transport System, ___ ATP are made, resulting in ___ ATP total.

2; 4

For each NADH made by glycolysis that enters the Electron Transport System, ___ ATP are made, resulting in ___ ATP total. The exception to this rule is in _______, _________, and ______ cells, where ___ ATP are made, resulting in ___ ATP total.

2; 4; heart; liver; prokaryotic; 3; 6

What is the total amount of ATP made from one molecule of glucose?

36 or 38

How much of the available energy of glucose is transferred to ATP?

39%

When does the process of fermentation occur?

if oxygen is not available

What does fermentation consist of?

glycolysis plus reduction of pyruvate to lactate or alcohol and CO2

Where and when does lactic acid fermentation occur in animals?

muscle cells when they exercise vigorously

What do bacteria use lactic acid fermentation for?

to convert milk into yogurt, sour cream, cheese, and some industrial chemicals

What happens in alcoholic fermentation?

yeast and other microorganisms produce ethanol and CO2 from pyruvate

Examples of alcoholic fermentation:

CO2 makes bread rise; wine, beer

How much ATP does fermentation produce?

2

What is an advantage of fermentation?

provides a quick burst of energy

What are disadvantages of fermentation?

low yield of ATP, lactate is toxic to cells, after exercise the body still needs oxygen to convert lactate to pyruvate in the liver

What is catabolism?

the process of breaking down larger molecules into smaller ones, releasing energy that can be used by the cell

What happens to glycerol during lipid catabolism?

it enters glycolysis

What happens to fatty acids during lipid catabolism?

enter Kreb’s Cycle as acetyl CoA

What happens to amino acids in catabolism?

deaminated in liver with the removal of the amino group; becomes ammonia; enters glycolysis, as acetyl CoA, or into Citric Acid Cycle

What is anabolism?

Anabolism is the process of building larger molecules from smaller ones, usually requiring energy (ATP); the converting of substances in metabolic pool to other substances

Examples of anabolism:

carbohydrates can be converted to fats, G3P to glycerol, acetyl groups to fatty acids

What are 4 similarities between photosynthesis and cellular respiration?

1. both use specialized organelles (chloroplasts and mitochondria)

2. both rely on membranes for reactions and gradients (thylakoid and cristae)

3. both depend on enzymes

4. both use ETCs to transfer electrons and generate ATP through chemiosmosis