Chapter 2: Metabolism: Energy Systems Flashcards
What are substrates?
nutrients from ingested foods such as CARBS, FATS and PROTEINS
- these nutrients can be broken down to release stored energy
What is bioenergetics?
a chemical pathway that convert substrates to usable energy
The energy we derive from food is stored in the cells in the form of what?
ATP
How is energy in biological systems measured?
kilocalories (KCal)
How much kilocalories is the amount of heat energy needed to raise from 14.5 to 15.5 degree celsius?
one kilocalorie
At rest, what does the body use for energy?
fat and carbs equally
At short and intense duration what does the body use for energy?
mostly carbs
At long and slow duration what does the body use for energy?
carbs and fat
What energy source uses little energy but serves as the building blocks for the body’s tissues?
protein
True or False. All dietary carbohydrate is ultimately converted to glucose.
TRUE
When is carbs used?
during aerobic and anaerobic exercise
When is fats used?
during aerobic exercise
What is the amount of kcals/g used in carbs?
4 kcals/g
What is the amount of kcals/g used in fats?
9 kcals/g
When is protein used?
5-10% of energy during prolonged exercise
True or False. Body stores of fat are larger than carbohydrate reserves
TRUE
What takes more time to breakdown? fat or carbohydrate?
FAT
What is carbohydrate converted to?
glucose
How is carbohydrate stored?
stored as glycogen in both liver and muscle
What happens to carbohydrates in liver?
carbohydrate is converted back to glucose
What happens to carbohydrates in liver?
used as ATP
How is fat stored?
stored as triglycerides
How is fat broken down?
broken down into free fatty acids used in metabolism
What is protein converted to?
converted into triglycerides
How is protein stored?
adipocytes
How is protein broken down?
glucose LESS ENERGY
amino acids MORE ENERGY
What is oxidation?
loss of electrons or hydrogen
What is reduction?
gain of electrons or hydrogen
What is phosphorylation?
addition of a phosphate
What is the two parts of phosphorylation?
- substrate level phosphorylation
2. oxidative phosphorylation: ET chain
What does a muscle cell contain?
- sarcoplasm
- mitochondria
Where does metabolism occur?
mitochondria
What is anabolic reaction?
building energy (REQUIRES)
What is catabolic reaction?
breaking down energy (RELEASES)
What is substrate availability?
- mass action effect
- cells will rely on most abundant
What are co-enzymes?
- non protein, vitamins and minerals
- NAD (nicotinamide adenine dinucleotide)
- FAD (flavin adenine dinucleotide)
What are enzymes?
- proteins
- biological catalyst
- remain intact
- “ase”
What is a biological catalyst?
- speed up reaction
- lowers activation threshold
What is rate-limiting enzyme?
SLOWS overall reaction, prevents runway reaction
What is influenced by accumulation of product further down via NEGATIVE FEEDBACK?
rate-limiting enzyme
What is mechanical work?
muscle contraction
What is chemical work?
building molecules, cells, structures
What is transport work?
moving nutrients & raw materials