Cellular Respiration and Metabolism

Question 1

difference between substrate level and oxidative phosphorylation

Answer 1

substrate - occurs in glycolysis and krebs cycle. transfer of P to ADP or GDP via a coupled reaction
oxidative - energy released by oxidation of nutrients produces ATP - ETC uses this

Question 2

where does glycolysis occur and what is the result

Answer 2

cytoplasm of the cell
1 6 carbon glucose = two pyruvate (3 carbon)
***anaerobic

Question 3

all the products of glycolysis

Answer 3

2 pyruvate 
2NADH
2H+
2ATP
2H2O

Question 4

as part of aerobic respiration where does the krebs cycle occur what is the result

Answer 4

matrix of the mitochondria
pyruvate produces 1ATP 3 NADH and 1FADH2, 2CO2
REMEMBER 2 PYRUVATE ARE PRODUCED SO DOUBLE THOSE AMOUNTS FOR 1 GLUCOSE YIELD

Question 5

where does ETC occur

Answer 5

inner membrane of mitochondria

Question 6

substrates of citric acid cycle

Answer 6

oxaloacetate
citrate
isocitrate
a-ketoglutarate
succinyl co a
succinate
fumarate
malate

Question 7

FAD and FMN are flavoproteins, what do they do

Answer 7

can accept or donate one or two electrons

Question 8

ATP derived from glycolysis

Answer 8

2 substrate level
6 from NADH oxidative phosphorylation
(Total subtract 2 because cost 2 to transport)

Question 9

ATP derived from the prep stage

Answer 9

reduction to 2 NADH = 6

Question 10

ATP derived from the krebs cycle

Answer 10

from 2 turns of the krebs cycle

2 GDP , 6 NADH, 2 FADH = 24

Question 11

what happens during the electron transport chain

Answer 11

energy released from the oxidation of NADH or FADH pumps protons into the intermembrane space
which creates an electrochemical gradient of protons. The proton motive force drives ATP synthase which adds a phosphate to ADP
Oxygen is reduced to form H20
reduction- oxidation reaction***

Question 12

net ATP from 1 glucose

Answer 12

36 ATP???

Question 13

under hypoxic conditions glycolysis is still possible to produce ATP but cystolic NAD is quickly depleted how do mammals continue to have glycolysis

Answer 13

fermentation**

pyruvate is converted to lactic acid which results in NAD+ which can go back into glycolysis

Question 14

how does fermentation work in yeast

Answer 14

pyruvate converted into acetylaldehyde then reduced to ethanol forms NAD+

Question 15

what are the two parts of the pentose phosphate pathway

Answer 15

oxidative branch: generates NADPH which regulates the pathway (not the same as NADH)
non-oxidative branch - creates 5 carbon sugar ribose

Question 16

in the absence of insulin what parts of the body still absorb glucose

Answer 16

brain and liver

Question 17

define glycogenolysis

Answer 17

when glycogen is broken down in the liver into glucose to be exported to the blood for transport

Question 18

what is gluconeogenesis

Answer 18

metabolic process that generates glucose from no carb substrates that have a 3 carbon back bone (lactic acid, glycerol, amino acid)
It it the reverse of glycolysis except a few steps where ATP is involved
*not fatty acids because they are broken down 2 carbons at a time into acetyl co A (which would then go to krebs)

Question 19

what is the major regulator for glycolysis, gluconeogenesis, glycogenolysis, glycogenesis

Answer 19

glucose - 6- phosphate

Question 20

two types of metabolism of fatty acids

Answer 20

turned into acetyl co A via beta oxidation by the organs they diffuse into
converted into ketone body via ketogenesis in the liver

Question 21

what is beta oxidation

Answer 21

when fatty acids are released from adipocytes and diffuse into tissues they are oxidized two carbons at a time.
in the mitochondria outer membrane fatty acid converted into acyl coA costs 1 ATP
acetyl co A is formed 2 carbon at a time in the matrix and then can enter the Krebs cycle
FADH and NADH are byproducts

Question 22

products of beta oxidation

Answer 22

FADH = 2 ATP
NADH = 3 ATP

Question 23

what is ketosis

Answer 23

during starvation liver converts fatty acids to acetyl co A, without insulin it gets converted by the mitochondria of liver cells into ketones which travel to other tissues and is converted back to acetyl co A then fed into krebs to make to make ATP

Question 24

what can use ketone bodies for energy and some examples

Answer 24

tissues other than RBC and the brain which can only use glucose
3 primary Ketones in the body : acetone, acetoacetic acid, beta hydroxybutyrate with a very polar carbonyl group

Question 25

BMI calculation, what is considered obese

Answer 25

kg/m^2

>30

Question 26

rate limiting enzyme for glycolysis

Answer 26

3rd step (fructose to glucose 1 phosphate ) phosphofructokinase 1 
1st step (glucose to fructose 6 phosphate) hexokinase
** each require input of ATP

Question 27

rate limiting enzyme fermentation

Answer 27

lactate dehydrogenase

Question 28

rate limiting enzyme glycogenesis

Answer 28

glycogen synthase

Question 29

rate limiting enzyme glycogenolysis

Answer 29

glycogen phosphorylase

Question 30

rate limiting enzyme gluconeogenesis

Answer 30

fructose 1 6 bi phosphate

Question 31

rate limiting enzyme pentose phosphate pathway

Answer 31

glucose 6 phosphate dehydrogenase

Question 32

What happens when pyruvate from glycolysis enters the mitochondria (prep stage)

Answer 32

Converted into coenzyme acetyl co A producing 2 NADH and CO2
This 2 carbon structure then goes to a 4 carbon structure to begin kerbs cycle

Question 33

What is NADPH

Answer 33

Can donate electrons

Used to prevent oxidative damage

Question 34

What happens in beta oxidation if the fatty acid chain has odd number of carbon

Answer 34

The last 3 carbons can ask as substrate for gluconeogenesis