Chapter 9 Flashcards
Carb involved in the TCA cycle that keeps it spinning?
oxaloacetate
What is another name for glycolysis and where does it occur?
anaerobic metabolism
cytosol
Component that connects metabolism of carbs, lipids, and proteins?
pantothenic acid-> Acetyl CoA
How many ATP formed in anaerobic metabolism of a carb?
2
How many ATP formed in aerobic metabolism of a carb?
30-32
What is the purpose of generating lactate in anaerobic metabolism?
replenish NAD+ supply
2 steps in fatty acid metabolism?
lipolysis-> beta oxidation (in mitochondria)
What can’t make glucose?
fatty acids
Acetyl CoA cannot be made into?
pyruvate
Ketogenesis
formation of ketone bodies (FA)
Acetone
ketone leaves body by lungs
Ketosis in Diabetes Miletus
rapid lipolysis-> ketosis-> diabetic ketoacidosis
Ketosis in semi-starvation
more gradual
What are 3 compounds formed by 2 Acetyl CoA?
Acetone
Acetoacetic Acid
beta-Hydroxybutyric acid
What occurs to blood-glucose levels during starvation?
- blood-glucose decreases
- breakdown of glycogen in muscles and liver increases blood-glucose
- blood-glucose decreases
- breakdown of fats-> fatty acids
breakdown of proteins-> AA-> glucose - ketones (FA)
What attributes to most of weight loss early on?
glycogen binds to H2O
What happens to glucose in type I diabetes?
cannot be taken in cell and remains in blood
increases in blood lipids, ketone bodies, and blood-glucose
Why are ketone bodies dangerous?
they are acidic and denature proteins which in turn, decrease blood pH which is dangerous for body functions
What is the purpose of forming ketones?
preserve body proteins and enable protein actions
Where does protein metabolism occur?
in liver
Where are branched chain amino acids metabolized?
by muscles
What occurs during the deamination stage?
protein (which contains N) has the element removed by vitamin B6 which results in a empty carbon skeleton
What vitamin can make other AAs?
Vitamin B6
Glycogenic AA
form pyruvate or bypass Acetyl CoA to enter citric cycles
* becomes glucose
Ketogenic AA
Acetyl-CoA (cannot become part of glucose)
* Acetyl-CoA (cannot form oxalacetate)
What is gluconegenesis?
formation of new glucose not from glucose
Where does gluconegenesis occur and what does it require?
in liver
ATP, B1, B2, B3, B6
What occurs after the deamination stage of protein metabolism?
excess AA is converted to Ammonia (NH3) and then into urea
Relationship between liver disease and ammonia?
can build up and cause blood toxicity
What is the toxic agent in kidney disease?
urea
carbs-> glycogen used for?
1.fatty acid synthesis
2.AA synthesis
3.formation of ATP
amino acids-> new body proteins used for?
new AAs
make glucose
make ATP
Fatty acid metabolism?
1.stored as fat/adipose tissue
2.produce ATP
3.produce ketone bodies
What organ is responsible for most nutrient interconversions?
liver
What does high ATP do to metabolism?
decrease glycolysis and promote anabolic reactions
What does high ADP do to metabolism?
stimulate energy yielding/catabolic pathways
Where does transition reaction occur?
pyruvate-> Acetyl-CoA
mitochondria
Where does fatty acid oxidation occur?
fatty acid-> Acetyl-CoA
mitochondria
Where does alcohol oxidation occur?
in cytosol and mitochondria
Where does the citric acid cycle occur?
mitochondria
Where does glyconeogenesis occur?
begins in mitochondria, then moves to cytosol
Alcohol uses niacin to become?
Acetyl-CoA
Fasting encourages?
-glycogen and fat breakdown
-gluconeogenesis
(from AAs taken from lean body tissue)
How does fasting encourage adaptation?
-decreases metabolic rate
-heart, muscles, kidney, and finally, the brain and CNS start burning ketones
Feasting encourages?
-insulin production
-glycogen synthesis
-protein and urea synthesis
Does consuming more protein increase muscle mass?
no
What increases carbohydrate conversion to body fat?
insulin
What are the products of carbohydrate breakdown?
-glucose
-fat
(requires high energy)
What are the products of Fatty acid breakdown?
-fat
(requires minimal energy)
What are the products of glycerol breakdown?
-glucose
-fat
(requires high energy)
What are the products of AA breakdown?
-glucose
-amino acids
-fat
(requires high energy)
What are the products of alcohol breakdown?
-fat
(requires high energy)
What errors could occur because of PKU?
-phenylalanine cannot be converted to tyrosine
-can cause retardation
What treatments are used for elevated PKU levels?
restrict phenylalanine (not eliminate)
What errors could occur because of galactosemia?
-galactose cannot be converted to glucose
What are treatments used for galactosemia?
most avoid all foods containing galactose
What occurs during glycogen storage disease?
liver cannot convert glycogen to glucose which causes a low BG
Carbs
4kcal
AMDR 45-65%
Protein
4kcal
Fat
9kcal
metabolism
network of chemical processes involved in maintaining life
anabolsim
process of building compounds
-requires ATP
catabolism
process of breaking down compounds
-to release and use energy
-P & ADP-> ATP
What is ATP used for?
-building compounds
-contracting muscles
-conducting nerve impulses
-pumping ions
ATP
adenine + ribose + 3 phosphate groups
-bonds high energy and hydrolysis of the bonds releases energy
-recycled
Oxidation-reduction reactions
-breakdown and release energy from macros
-antioxidant defense
Macro usage at sedentary lifestyle?
90% lipid
10% carb
-sufficient oxygen
Macro usage at increased intensity?
10% lipid
90% carb
Glycolysis (anaerobic)
-2 NADH & 2 ATP produced
-occurs in cytosol
-glucose oxidized to form 2 pyruvate
Vitamin needed to begin glycolysis?
niacin (NAD)
Vitamins needed to begin transition reaction?
B1, B2, B3, B5
Transiton reaction?
pyruvate oxidized-> 2 Acetyl CoA
-2 NADH produced
Products of Citric Acid Cycle?
6NADH
H+
2FADH2
2 ATP
2 GTP
Where does electron transport chain occur?
mitochondria
Oxidative phosphyrolyation?
electron transfers-> ATP
Electron Transport chain products?
10NADH
2FADH2
2GTP
2ATP
Final ATP production of electron transport chain?
28 ATP
Do all cells have mitochondria?
no, therefore, some aren’t capable of aerobic metabolism
What happens without oxygen in metabolism?
pyruvate-> lactic acid
Why is NAD+ regeneration crucial?
allows anaerobic glycolysis to continue
(by lactic acid)
low BG?
glucagon-> liver-> glycogen-> glucose
how many acetyl CoA does glucose form?
2
20 carbon fatty acids->
10 acetyl CoA
30 carbon fatty acids->
15 acetyl CoA
What is lipolysis?
triglycerides -> FAs and Glycerol
What enzyme enhances lipolysis?
hormone sensitive lipase (HSL)
What stimulates lipolysis?
glucagon, growth hormone, epinephrine
What inhibits lipolysis?
insulin
What occurs during beta oxidation?
-fatty acids transported from cytosol to mitochondria by carnitine
-works better when carbs present
-yields more energy than glucose oxidation
Fat metabolism
- Higher levels of oxaloacetate (a carb) needed to combine with acetyl-CoA to form citrate
- Pyruvate-> oxaloacetate (keeps cycle going)
