Unit #5: Metabolism

Question 1

How does electron transfer impact ATP synthesis?

Answer 1

Electron transfer releases energy that is converted to ATP.

Question 2

What is the purpose of NAD+ in metabolism?

Answer 2

Strong oxidizing agent that shuttles electrons. Reduced form is NADH.

Question 3

What is the final electron acceptor in eukaryotes?

Answer 3

Oxygen

Question 4

What is substrate level phosphorylation? Where does it occur?

Answer 4

The process of an enzyme directly adding a third phosphate onto an ADP. Occurs in glycolysis and fermentation, as well as inside the mitochondrial matrix in the citric acid cycle.

Question 5

What is oxidative phosphorylation? Where does it occur?

Answer 5

It is the process of phosphorylating an ADP through redox reactions. Occurs in the electron transport chain in the mitochondrial membrane.

Question 6

What is the monomer of carbohydrates?

Answer 6

Sugar

Question 7

All sugars have what group?

Answer 7

1 carbonyl group (C double bonded to O)

Question 8

What is the carbohydrate dehydration reaction called?

Answer 8

Glycosidic linkage

Question 9

What is the structural difference between beta and alpha glycosidic linkages?

Answer 9

In alpha linkages, the hydroxyl groups are symmetrical, in beta linkages the hydroxyl groups are not symmetrical.

Question 10

What are alpha linked carbohydrates used for?

Answer 10

Storage

Question 11

What are beta linked carbohydrates used for?

Answer 11

Structure

Question 12

What are disaccharides?

Answer 12

Sugars made of two monosaccharides linked by hydrogen bonds.

Question 13

In what order are the metabolic pathways thought to have evolved?

Answer 13

Glycolysis, fermentation, anaerobic respiration, photosynthesis, aerobic respiration.

Question 14

In glycolysis what do we put in and what are our products?

Answer 14

We put in 2 ATP, 1 glucose, 4 ADP and 2 NAD+

Our products are 4 ATP, 2 pyruvate and 2NADH

Question 15

What is the purpose of fermentation?

Answer 15

To oxidize NADH to regenerate NAD+ so glycolysis can continue.

Question 16

What type of fermentation do yeast go through?

Answer 16

Ethanol fermentation

Question 17

Outline the steps of ethanol fermentation.

Answer 17

Two pyruvate get decarboxylated, producing 2 Acetaldehyde, which then accept electrons from the 2 NADH, producing 2 NAD+ and 2 ethanol.

Question 18

What type of fermentation do humans go through?

Answer 18

Lactic acid fermentation

Question 19

Outline the steps of lactic acid fermentation.

Answer 19

2 pyruvate reduced to 2 lactate

Question 20

Which two ways can pyruvate go after glycolysis?

Answer 20

Fermentation in no oxygen present or anaerobic respiration if oxygen is present.

Question 21

What is the first step of cellular respiration and outline its steps.

Answer 21

Pyruvate oxidation in the mitochondrial matrix, 2 pyruvate get oxidized producing 2 Acetyl-CoA and 2 NADH.

Question 22

Where does cellular respiration occur?

Answer 22

Mitochondria, as pyruvate travels from cytoplasm to mitochondria.

Question 23

What is the Citric Acid Cycle?

Answer 23

A cyclic series of enzymatic reactions requiring the Acetyl-CoA to produce product.

Question 24

Per glucose, what are the end products of the Citric Acid Cycle.

Answer 24

2 CoA, 4 CO2, 6 NADH, 2 ATP, 2 FADH2

Question 25

What is the electron transport chain?

Answer 25

A series of electron carriers embedded in the mitochondrial membrane that take electrons from FADH2 and NADH. This process produces ATP.

Question 26

How exactly does the ETC produce ATP.

Answer 26

The combination of energy released from the redox reactions coupled with moving protons against their concentration gradient.

Question 27

If the protons were to move with their concentration gradient (high to low) where in the mitochondria would they move?

Answer 27

From the intermembrane space to the mitochondrial matrix.

Question 28

How do you tell if respiration is anaerobic?

Answer 28

If the final electron acceptor in the ETC is not oxygen.

Question 29

When protons get pumped out into the intermembrane space through the redox reactions, they want to go down their concentration gradient, therefore back into the matrix. How do they do this?

Answer 29

By diffusing through an intermembrane protein called ATP Synthase, producing ATP as the protons move through.

Question 30

How many protons are required to pass through the ATP Synthase to produce 1 ATP

Answer 30

4 protons

Question 31

What is the movement of protons down their concentration gradient called?

Answer 31

Chemiosmosis

Question 32

Rate the three methods of energy product high to low based on efficiency.

Answer 32

1. Aerobic respiration 2. Anaerobic respiration 3. Fermentation

Question 33

Do heterotrophs or autotrophs directly depend on photosynthesis?

Answer 33

Autotrophs

Question 34

Is photosynthesis catabolic or anabolic

Answer 34

Anabolic

Question 35

Where does photosynthesis occur?

Answer 35

The chloroplast

Question 36

Where do the light reactions occur?

Answer 36

Thylakoids

Question 37

What are stacks of thylakoids called?

Answer 37

Grana

Question 38

Where does the Calvin Cycle occur?

Answer 38

Stromata

Question 39

Which pigment do all plants contain?

Answer 39

Chlorophyll A

Question 40

What comes first? Photosystem I or II?

Answer 40

Photosystem II

Question 41

What oxidizes water during the light reactions?

Answer 41

P680

Question 42

What are the products of the light reactions?

Answer 42

ATP, NADPH, O2

Question 43

What are the external inputs of light reactions (not from Calvin Cycle)

Answer 43

Light and water

Question 44

What are the products of the Calvin Cycle?

Answer 44

ADP, NADP+ and sugar.

Question 45

What are the external inputs of Calvin Cycle (not coming from light reactions)?

Answer 45

CO2

Question 46

What is the enzyme that drives the Calvin Cycle?

Answer 46

Rubisco

Question 47

What are the three steps of the Calvin Cycle?

Answer 47

Fixation, Reduction, Regeneration.

Question 48

What occurs in the fixation phase of the Calvin Cycle?

Answer 48

The carbon from CO2 is stripped and added to an intermediate in the Calvin Cycle.

Question 49

What occurs in the reduction phase of the Calvin Cycle?

Answer 49

An intermediate gets reduced and phosphorylated, producing 6 sugars called G3P. 1 of which leaves the Calvin Cycle, and the rest move on to the regeneration phase.

Question 50

What occurs in the regeneration phase of the Calvin Cycle.

Answer 50

ADP is phosphorylated, and RuBP is regenerated.

Question 51

When NADH donates electrons, how many protons are pumped into the intermembrane?

Answer 51

10

Question 52

When FADH2 donates electrons, how many protons are pumped into the intermembrane?

Answer 52

6