metabolism study guide

Question 1

Every cell acquires _________.

Answer 1

nutrients

Question 2

Cellular energy is stored in ________.

Answer 2

ATP (Adenosine Triphosphate)

Question 3

Precursor Metabolite:

Answer 3

products in catabolic pathways & used for raw materials for anabolic pathways

Question 4

Catabolism:

Answer 4

All decomposition reactions in a living organism; the BREAKDOWN of complex organic molecules into simpler ones.
(think of a CATaboilism BREAKING DOWN all the glass in your house).

Question 5

Anabolism:

Answer 5

All SYNTHESIS reactions in a living organism, the BUILDING of complex organic componds into simpler ones.

Question 6

Metabolic pathway:

Answer 6

A sequence of enzymatically catalyzed reactions occuring in a cell. (End product)

Question 7

Activation energy

Answer 7

The minimum collision energy required for a chemical reaction to occur.
remember: ENZYMES reduce amount of activation energy

Question 8

Amphibolic pathway:

Answer 8

A pathway that is both anabolic and catabolic.

Question 9

Substrate:

Answer 9

A compund with which and enzyme reacts or acts up.

Question 10

In a redox reaction, which is being reduced?
-electron donor
-recipient

Answer 10

Oxidation
Is
Lost
Reduction
Is
Gained
-Electron donor (becomes oxidized)
-Electron acceptor (becomes reduced)

Question 11

-Biological catalysts are called __________.
-What are the componets of this catalyst?

Answer 11

-Enzyme
-Components of enzyme:
—apoenzyme (protein portion)
—cofactor (non protein portion, aka coenzyme)
apoenzyme+cofactor create the holoenzyme

Question 12

What are other characteristics of this catalyst (enzyme): can be used more than once

Answer 12

-specific for a substrate → products
-speeds up reactions (catalyst)
-they are not permanently changed in the reaction.
-lowers activation energies(→amount of energy it takes to start a reaction).

Question 13

What are some environmental or physical factors that influence enzyme activity? explain.

Answer 13

1. Temperature (enzyme activity decreases). optimalmeaining if its too cold→ it may not operate. if its too high →it could be disturbed.
2. pH (denatures enzymes) most operate at pH 7.
3. Enzyme and substrate concentrations
4. Presence of inhibitors

Question 14

What are some chemical factors that can inhibit enzyme activity?

Answer 14

-competitive inhibitors
-non competitive or allosteric inhibitors
-too much product
PHYSICAL FACTOR: substrate concentration

Question 15

What is phosphorylation? What types are there?

Answer 15

Phosphorylation: the addition of a phosphate group to an organic molecule.
Types:
1.Substrate-level phosphorylation (taken from molecules)
2. Oxidative phosphorylation (happens at the end of cellular respiration)
3. Photosphorylation-happens in photosynthesis→ETC, creation of a proton gradient, harvesting energy of the proton gradient by making ATP.

Question 16

What type of phosphorylation occurs in glycolysis?

Answer 16

Substrate-level phosphorylation (also occurs in Krebs Cycle)

Question 17

What type of phosphorylation occurs in the Electron Transport Chain (ETC)?

Answer 17

2 parts: occurs in oxidative phosphorylation and chemiosmosis.

Question 18

TRUE or FALSE:
Glycolysis is driven by the presence of oxygen.

Answer 18

FALSE
-glycolysis is an anaerobic process, produces minimal amount of ATP.
On the other hand……
Krebs Cycle & ETC do need oxygen to proceed, and in presence of oxygen, these processes produce much more ATP than glycolysis alone.

Question 19

How many ATPs are formed from Glycolysis?

Answer 19

4 ATP.

Question 20

What is the net gain of ATP?

Answer 20

Only 2(basically paying off debts)

Question 21

What are all products of glycolysis?

Answer 21

2 pyruvic acid + 2ATP +2NADH +2H

Question 22

What product of the intermediate step enters the Krebs Cycle?

Answer 22

2 molecules of acetyl-coA

Question 23

___ molecules of ATP are made in the Krebs cycle by ___________ phosphorylation.

Answer 23

1 molecule
Sub-level phosphorylation

Question 24

What waste product is given off as the organic acids become decarboxylated?

Answer 24

CO₂

Question 25

What kinds and how many of each electron carriers have been reduced during the Krebs cycle?

Answer 25

3NADH, 1FADH₂

Question 26

How many times does the Krebs cycle go around for one molecule of Glucose?

Answer 26

For one molecule of Glucose, there’ll be two rounds of Krebs cycle ( one for each acetyl coA).

Question 27

Electrons are passed along a series of carrier molecules in a system called ______.

Answer 27

Electron transport chain (ETC).

Question 28

In the ETC, ATP is made by _______ phosphorylation.

Answer 28

Oxidative

Question 29

What term is used to describe the build up the hydrogen proton gradient on one side of the membrane?___________.

Answer 29

Chemiosmosis

Question 30

The membrane in prokaryotes is the_____________.

Answer 30

Plasma membrane

Question 31

The membrane in eukaryotes?

Answer 31

Mitochondrial inner membrane.

Question 32

Name the enzyme that allows the protons to rush to the other sides.

Answer 32

ATP synthase

Question 33

What is the final electron acceptor in aerobic respiration?

Answer 33

Oxygen

Question 34

-Are there electron transport chains in anaerobic respiration?
-What does it use for a final electron acceptor?

Answer 34

-
-Sulfate, Nitrate, Bicarbonate.

Question 35

Is there glycolysis in anaerobic respiration?

Answer 35

Yes, glycolysis is independent in both anaerobic and aerobic respiration.

Question 36

What are the products of fermentation?

Answer 36

Ethanol
Lactic acid
Sometimes CO₂ and some acids

Question 37

Examples of how fermentation is useful to humans

Answer 37

Carbs
The food we eat
Extending shelf life of foods…

Question 38

Explain why humans and some bacteria and fungi are called chemoheterotrophs

Answer 38

Chemoheterotroph:derives its energy from chemicals/needs to consume other organisms in order to live.
Humans, bacteria, and fungi could be called chemoheterotrophs because they use organic carbon for their source of energy and for their main source of carbon

Question 39

List the various reactions involved in the catabolism of a protein

Answer 39

Deamination, decarboxylation, dehyrdrogenation, organic acid
Protease breaks down polypeptides=lots of amino acids
Lastly they go to the Krebs Cycle

Question 40

Respiration Reaction: Glucose reduced to Carbon Dioxide. Know where we find each one.
C6H12O6+6O₂=6CO₂+6H₂O+38ATP+Heat
Where does C6H12O6 happen?

Answer 40

C6H12O6 happens in the beginning of Glycolysis.

Question 41

Respiration Reaction: Glucose reduced to Carbon Dioxide. Know where we find each one.
C6H12O6+6O₂=6CO₂+6H₂O+38ATP+Heat
Where does 6O₂ happen?

Answer 41

6O₂ happens in the electron transport chain

Question 42

Respiration Reaction: Glucose reduced to Carbon Dioxide. Know where we find each one.
C6H12O6+6O₂=6CO₂+6H₂O+38ATP+Heat
Where does 6CO₂ comes from?

Answer 42

6CO₂ comes from an intermediate step & Krebs Cycle.

Question 43

Respiration Reaction: Glucose reduced to Carbon Dioxide. Know where we find each one.
C6H12O6+6O₂=6CO₂+6H₂O+38ATP+Heat
Where does 6H₂O occur?

Answer 43

6H₂O occurs at the end of ETC.

Question 44

Respiration Reaction: Glucose reduced to Carbon Dioxide. Know where we find each one.
C6H12O6+6O₂=6CO₂+6H₂O+38ATP+Heat
Where does 38ATP occur?

Answer 44

38 ATP occurs in glycolysis, Krebs cycle, and ETC