Chapter 5 Flashcards
What is metabolism?
combined catabolic and anabolic reactions in a body
What is catabolism?
breaking down molecules and releasing energy
What is anabolism?
synthesizing molecules and NEEDS energy
Is glycolysis anaerobic or aerobic?
anaerobic
What is glycolysis?
pathway where glucose is converted into 2 pyruvates
What is the net equation for glycolysis?
glucose + 2 NAD + 2 ADP + 2Pi -> 2 pyruvates + 2 NADH + 2 ATP
Is glycolysis exergonic or endergonic?
exergonic
- produces energy
Why does the reaction begin with glucose turning into G6P?
phosphorylation traps glucose inside cell
What is the ATP exchange in glycolysis?
uses 2 ATP to make 4 ATP
Why do we need to make lactic acid?
to avoid end-product inhibition
- NADHs produced in glycolysis needs to give hydrogens away
How does lactic acid pathway work?
without oxygen, NADH gives hydrogens to pyruvate to make lactic acid
What is the net gain in the lactic acid pathway?
2 ATPs per glucose
What blood cell only uses lactic acid pathway? Why?
red blood cells
- no mitochondria
Where does the lactic acid pathway occur?
skeletal and heart muscle when oxygen supply falls below critical level
How is glucose stored?
as glycogen (long glucose chains)
What is glycogenolysis?
clips glucose out of glycogen as G6P
What is the only organ that can remove phosphate groups?
liver has glucose-6-phosphatase and can secrete glucose
What is the cori cycle?
lactic acid -> pyruvate -> glucose and glycogen
- gluconeogenesis (reverse glycolysis)
How does aerobic respiration start?
pyruvate enters mitochondria
- CO2 clipped off pyruvate to form acetyl CoA
How does Krebs Cycle start?
acetyle CoA combines with oxaloacetate to make citrate
What does the Krebs Cycle produce?
1 GTP, 3 NADH, 1 FADH2
How does FADH2 and NADH get converted to energy (ATP)?
by carrying electrons to the electron transport chain
What proteins are involved in the ETC?
FMN, coenzyme Q and cytochromes
Where does ETC occur?
cristae of mitochondria
Is ETC endergonic or exergonic?
exergonic
- energy is used to phosphorylate ADP to make ATP (oxidative phosphorylation)
How does the ATP synthase work?
- energy gathered from ETC pumps H+ into mitochondrial outer chamber (high H+ concentration)
- H+ diffuses down concentration and charge gradient and back into their inner chamber
What is the chemiosmotic theory?
how ETC work and how the energy released by the transfer of electrons to create an electrochemical gradient across a membrane
What happens to the electrons added to ETC?
reaches the end and O2 accepts them to make water
What are the 2 ways ATP is made?
1) Direct (substrate-level) phosphorylation
- 2 ATP in glycolysis
- 2 ATP in Krebs
2) Oxidative phosphorylation in Krebs cycle (ETC)
- 30-32 ATPs
How many ATP is made in ETC?
3 (or 4) H+ forms 1 ATP
- makes 26 ATP
How many ATP is made from NADH? FADH2?
1 NADH = 3 ATP
1 FADH2 = 2 ATP
What is the total ATP production?
26 ATP from ETC
2 ATP from glycolysis
2 ATP from Krebs
= 30 ATP/glucose
How are fats used as energy?
hydrolyzed to glycerol and fatty acids
How can proteins be used as energy?
broken down to amino acids
- can be deaminated and r=
What is acetyl CoA?
substrate for energy and synthetic pathways
What is fat? (triglycerides)
fatty acid + glycerol
What is the main form of energy storage?
fat
- 9 kcal/g
What is lipolysis?
breakdown of fat into fatty acids and glycerol
- hydrolysis
What is beta-oxidation?
clips acetyl CoA off of fatty acid chains
What is transamination?
interconverts amino acids
What is deamination?
removes amino group
