Module 16- Metabolism Flashcards
what is metabolism?
how we extract and store energy from absorbed nutrients
what is ATP?
adenosine triphosphate
it powers the cells in your body
ex. na/k pump, releasing actin from myosin, etc
What are proteins digested as?
Amino acids
What are carbohydrates digested as?
monosaccharides
we mainly consider glucose
What are fats digested as?
fatty acids and gylcerol
monoglycerides and cholesterol too
What are the four fuels our body uses for energy?
amino acids, glucose, fatty acids, glycerol
anabolism
taking smaller units (ex. absorbable nutrients like glucose) and building them into larger molecules for STORAGE
How is excess glucose stored?
as GLYCOGEN
a limited amount is stored in muscle/liver tissue, or other cells (except brain)
once ^ fill with glycogen, the rest becomes TRIGLYCERIDES to be stored in adipose tissue
How is excess amino acids stored?
instead of stored as protein in muscle, its stored as TRIGLYCERIDES in the adipose tissue (as fat)
How is excess fat stored?
stored as TRIGLYCERIDES (fat) in adipose tissue
What percent of cell energy is generated in the cell from glucose?
1% total body energy
stored as glycogen in limited amounts
What percent of cell energy generated in the cell from fatty acids?
77% total body energy
fatty acids taken from adipose storage
what percent of cell energy generated in the cell from amino acids?
22% total body energy (IF NEED BE)
last resort if all other resources have been used up
will have to sacrifice muscles in order to generate energy, only happens due to malnourishment
what are the 3 reactions that the cell carries out to produce ATP from nutrients?
1) Glycoysis–> 2 ATP
2) Citric Acid Cycle–> 2 ATP
3) Oxidative Phosphorylation–> 34 ATP
what is glycolysis
- 2 ATP from 1 glucose
- occurs in CELL CYTOPLASM
- no oxygen required
what is Citric Acid Cycle (CAC)
- 2 ATP from 1 glucose
- mitochondria
- requires oxygen
what are the by-products of creating ATP?
CO2 and water
what stage of energy cycle does glucose enter?
beginning of glycolysis
what stage of energy cycle does amino acids enter?
-convert to acetyl CoA–> CAC
OR
-convert to pyruvate–> glycolysis
what stage of energy cycle does triglycerides enter?
- 1st broken down into FATTY ACIDS and GLYCEROL
- glycerol enters at glycolysis
- fatty acid–> converted to acetyl CoA–> CAC
can the brain store glycogen?
no it cannot
which energy source can the brain ONLY use?
glucose
after eating, our blood has lots of glucose circulating. explain how cells change glucose into G6P
- cells turn glucose into GLUCOSE 6 PHOSPHATE
- G6P has 2 options:
1) enter glycolysis for atp
2) be stored as glycogen
glycogen. …
2a) it can be converted back to G6P to make atp later
2b) G6P goes thru a rxn to make atp and PYRUVATE
3) PYRUVATE has 2 options :
3a) WITH oxygen–> CAC
3b) NO oxygen–> LACTIC ACID
what is the purpose of lactic acid?
- when exercising, blood cant be pumped fast enough to bring enough o2 to muscle cells for making atp with CAC
- glycolysis is anaerobic (no o2 needed to rxn) but produces a lot of PYRUVATE
- too much pyruvate is BAD–> solution= create lactic acid