Cellular Respiration and Metabolism Flashcards
difference between substrate level and oxidative phosphorylation
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
where does glycolysis occur and what is the result
cytoplasm of the cell
1 6 carbon glucose = two pyruvate (3 carbon)
***anaerobic
all the products of glycolysis
2 pyruvate 2NADH 2H+ 2ATP 2H2O
as part of aerobic respiration where does the krebs cycle occur what is the result
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
where does ETC occur
inner membrane of mitochondria
substrates of citric acid cycle
oxaloacetate citrate isocitrate a-ketoglutarate succinyl co a succinate fumarate malate
FAD and FMN are flavoproteins, what do they do
can accept or donate one or two electrons
ATP derived from glycolysis
2 substrate level
6 from NADH oxidative phosphorylation
(Total subtract 2 because cost 2 to transport)
ATP derived from the prep stage
reduction to 2 NADH = 6
ATP derived from the krebs cycle
from 2 turns of the krebs cycle
2 GDP , 6 NADH, 2 FADH = 24
what happens during the electron transport chain
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***
net ATP from 1 glucose
36 ATP???
under hypoxic conditions glycolysis is still possible to produce ATP but cystolic NAD is quickly depleted how do mammals continue to have glycolysis
fermentation**
pyruvate is converted to lactic acid which results in NAD+ which can go back into glycolysis
how does fermentation work in yeast
pyruvate converted into acetylaldehyde then reduced to ethanol forms NAD+
what are the two parts of the pentose phosphate pathway
oxidative branch: generates NADPH which regulates the pathway (not the same as NADH)
non-oxidative branch - creates 5 carbon sugar ribose
in the absence of insulin what parts of the body still absorb glucose
brain and liver
define glycogenolysis
when glycogen is broken down in the liver into glucose to be exported to the blood for transport
what is gluconeogenesis
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)
what is the major regulator for glycolysis, gluconeogenesis, glycogenolysis, glycogenesis
glucose - 6- phosphate
two types of metabolism of fatty acids
turned into acetyl co A via beta oxidation by the organs they diffuse into
converted into ketone body via ketogenesis in the liver
what is beta oxidation
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
products of beta oxidation
FADH = 2 ATP NADH = 3 ATP
what is ketosis
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
what can use ketone bodies for energy and some examples
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
BMI calculation, what is considered obese
kg/m^2
>30
rate limiting enzyme for glycolysis
3rd step (fructose to glucose 1 phosphate ) phosphofructokinase 1 1st step (glucose to fructose 6 phosphate) hexokinase ** each require input of ATP
rate limiting enzyme fermentation
lactate dehydrogenase
rate limiting enzyme glycogenesis
glycogen synthase
rate limiting enzyme glycogenolysis
glycogen phosphorylase
rate limiting enzyme gluconeogenesis
fructose 1 6 bi phosphate
rate limiting enzyme pentose phosphate pathway
glucose 6 phosphate dehydrogenase
What happens when pyruvate from glycolysis enters the mitochondria (prep stage)
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
What is NADPH
Can donate electrons
Used to prevent oxidative damage
What happens in beta oxidation if the fatty acid chain has odd number of carbon
The last 3 carbons can ask as substrate for gluconeogenesis
