cellular respiration

Question 1

cellular respiration

Answer 1

• opposite of photosynthesis
• depends on O2 (aerobic)
• extracts energy from food (glucose and others)
• yields 34-38 atp

Question 2

4 parts of mitochondria

Answer 2

1. outer membrane
2. inner membrane
3. matrix
4. intermembrane space

Question 3

glucose

Answer 3

• only 40% of E in glucose gets stored as atp
• 60% is lost as heat to environment
• glucose is completely broken down into CO2 and H2O

Question 4

electrons

Answer 4

• glucose’s energy is stored as e-
• during cellular respiration, e- are transferred to various receptors, such as oxygen
• you can’t see the transfer of e-, just the H distribution (representation of e- transfers)

Question 5

redox

Answer 5

reduction/oxidation reaction

Question 6

oxidation

Answer 6

loss of e- or H+

Question 7

reduction

Answer 7

gain of e- or H+

Question 8

coenzymes

Answer 8

NAD+ (nicotinamide adenine dinucleotide)
FAD (flavin adenine dinucleotide)
CoA (coenzyme A)

Question 9

enzymes

Answer 9

• dehydrogenase

- NAD (oxidized) -> NADH (reduced)

Question 10

5 stages of glucose breakdown

Answer 10

1. glycolysis
2. acetyl CoA
3. Krebs cycle / citric acid cycle
4. electron transport
5. chemisomosis

Question 11

location of glycolysis

Answer 11

cytosol

Question 12

location of acetyl CoA

Answer 12

matrix

Question 13

location of Krebs/cac

Answer 13

matrix

Question 14

location of electron transport

Answer 14

inner membrane

Question 15

location of chemiosmosis

Answer 15

intermembrane space, inner membrane and matrix

Question 16

products of glycolysis

Answer 16

• net 2 ATP
• 2 NADH
• 2 pGAL/G3P
• 2 pyruvic acid / pyruvate

Question 17

glycolysis

Answer 17

all organisms do this

irreversible

Question 18

phosphofructokinase

Answer 18

regulates glycolysis in step 3

ATP inhibits phosphofructokinase

Question 19

acetyl CoA step

Answer 19

• 2 oxygen pulls off a C and leaves as CO2
• 2 NADH
• ES complex, acetyl CoA

Question 20

Citric Acid / Krebs Cycle

Answer 20

• 6 NADH
• 2 FADH2
• 4 ATP
• 4 CO2

Question 21

Krebs Cycle

Answer 21

• lies at the intersection of anabolism and catabolism
• high ATP = anabolism
• low ATP = catabolism

Question 22

electron transport

Answer 22

• the pathway of an electron from one carrier to another
• electrons are released when a carrier becomes oxidized
• mitochondria in eukaryotes and cell membrane in prokaryotes

Question 23

electron transport chain

Answer 23

• cytochrome

- special membrane proteins that transport electrons

Question 24

cytochrome

Answer 24

special membrane proteins that transport electrons

Question 25

intermembrane vs matrix

Answer 25

- matrix has low H+ - matrix is constantly being drained of its H+ - this creates an electrochemical gradient

Question 26

NADH and FADH2

Answer 26

- for every 1 NADH and FADH2, 3 H+ move into the intermembrane space against the concentration gradient without ATP - 10 NADH = 30 H+ removed

Question 27

ATP synthase

Answer 27

- (aka ATP synthetase) - because of the gradient, ATP wants to go back into the gradient - the only way back is through a protein complex called ATP synthase - the outflow of H+ works like a turbine and actually uses the free energy to change ADP back to ATP

Question 28

oxidative phosphorylation

Answer 28

- the energy from all the Cs is transferred to phosphorous bonds in ATP - chemiosmosis only

Question 29

how much ATP?

Answer 29

- glycolysis: net 2 - acetyl CoA: 0 - Krebs: 2-4 - E- transport: 0 - chemiosmosis: 28-32 - total: 30-38

Question 30

why does atp synthesis vary in chemiosmosis

Answer 30

- NADH and FADH2 don't always donate 2 e = less - they may not have picked up 2 e in the first place = less - more than 10 NADH or FADH2 may be involved = more

Question 31

poisons that interrupt cellular respiration

Answer 31

insecticides antibiotics research to understand mechanisms

Question 32

anaerobic

Answer 32

- no oxygen - some prokaryotes require this (Clostridium botulinum) - can show up in muscles while exercising

Question 33

lactic acid fermentation

Answer 33

- fermentation (cytoplasm) - must use pyruvate to reduce NADH and NAD+ - lactic acid (lactate) produced - if O2 is added it will switch to the Krebs cycle

Question 34

uses of lactic acid fermentation

Answer 34

- used to make cheese - turns soy beans into soy sauce - cabbage turns into sauerkraut

Question 35

alcohol fermentation

Answer 35

- yeast/bacteria - converting pyruvate to CO2 (bubbles) and ethanol - yeast: alcoholic beverages - wine: yeast dies at 14% (alc)

Question 36

strict aerobes

Answer 36

must have oxygen

Question 37

strict anaerobes

Answer 37

must be without oxygen (stagnant ponds / deep in soil)

Question 38

facultative anaerobes

Answer 38

can go back and forth between O2 and no O2

Question 39

other organic molecules for fuel

Answer 39

- digestion breaks polymers to monomers, enzymes change monomers into intermediates for cellular respiration - simple sugars -> glucose and isomers - fatty acids -> acetyl CoA - amino acids -> pyruvate, acetyl CoA, Krebs cycle