Unit 2 Animal Phsy

What type of chemical bonds store energy in ATP and GTP

High-energy hydrogen phosphate bonds

What is the phosphagen system

A rapid energy system where muscle cells store phosphocreatine to maintain ATP levels during high demand

How is ATP replenished in cells

From teh phosphate gradient using energy
ADP+ Pi → ATP

How does phosphocreatine regenerate ATP

Phosphocreatine transfers a phosphate to ADP via creatine kinase
ADP+PCr→ATP+Cr

Why is ATP considered unstable at high concentrations

It breaks down easily, so phosphocreatine buffers ATP levels

How much energy does phosphocreatine donate to regenerate ATP

10 kcal/mol anaerobically

What is required to rebuild phosphocreatine after use

Surplus energy, typically from aerobic metabolism (oxygen)

How does ATP transfer energy in cells

By reversible phosphate bond transfer, not destruction of the whole molecule

What reaction couples ATP regeneration with phosphocreatine use

ADP+PCr→ATP+Cr

How does creatine supplementation affect muscle cells

Increase phosphocreatine synthesis, improving strength and performance

What happens to ATP and phosphocreatine during repeated contractions

Both become progressively depleated

What provides immediate energy during muscle contractions

Stored ATP, followed quickly by phosphocreatine

What regenerates ATP after ATP and PCr are depleated

Metabolic pathways (glycolysis, TCA cycle, ETC)

What is metabolism

Conversion of fuels into ATP

What role does acetyl-CoA play in metabolism

Links glycolysis, Krebs cycle, and electron transport chain

Where does glycolysis occur

In the cytoplasm of all cells

How many carbons are in glucose

six

How is glucose stored in the body

As glycogen, a branched glycose polymer

What molecule begins glycolysis

Glucose

Why is glucose a stable energy molecule

Energy is stored safely in carbon-hydrogen bonds

What is the ATP investment phase of glycolysis

2 ATP are used to form fructose-1, 6-biphoshphate

What happens in glycolysis after ATP investment

Glucose splits into two 3-carbon molecules

Is carbon lost during glycolysis

No, all 6 are conserverd

How is ATP generated in glycolysis

By substrate-level phosphorylation

What molecule donates phosphate to form ATP in glycolysis

Phosphoenolpyruvate (PEP)

What is the net reaction of glycolysis

Glucose→2 pyruvate

What is the net yeild of glycolysis per glucose

2 ATP, 2 NADH, 2 pyruvate, 2 H2O

Why is pyruvic acid potentially harmful

Increases H+ concentration, disrupting protein function

Why is glycolysis inefficient long-term

Produces ATP quickly but generates toxic byproducts

How is pyruvate detoxified anaerobically

Converted to lactate

Does glycolysis require oxygen

No

What is the Cori cycle

Conversion of muscle lactate into glucose in the liver

What is another name for the Cori cycle

Lactic acid cycle

What is the ATP cost of converting lactate to glucose

6 ATP

What is the net ATP loss of the Cori cycle

-4 ATP per cycle

Why is glycolysis still useful despite energy loss

Provides rapid ATP during intense stress

What is meant by oxygen debt

Extra oxygen needed later to repay anaerobic ATP production

How many ATP does glycolysis yeild per glucose overall

2 ATP

What happens to pyruvate when oxygen is available

Enters mitochondria for further ATP production

Why do phylogenic affinities complicate adaptation interference

Closely related species share traits due to ancestry, not necessarily environmental adaptation

Why can phenotypic similarities be misleading in adaptation studies

Similar traits may reflect shared phylogeny rather than adaptive evolution

What does regression without phylogeny assume

Species are phylogenetically independent, so variation reflects noise rather than adaptation

What does a regression showing no trend imply without phylogenetic context

No detectable adaptation, only variability

How does knowing phylogeny improve adaptation interference

It allows divergent traits to be attributed to adaptation rather than shared ancestry

Why are phylogenetic comparative methods important

They distinguish true adaptation from acclimatization across related species

What role do subsets play in experimental design

Valid partitioning (ex: day vs night) reveals environmental response patterns

Why does maintaining homeostasis require energy

Internal conditions must be regulated despite external variability, requiring metabolism

Why is metabolism less variable than the environment

It buffers organisms against external fluctuations to maintain homeostasis

What is cellular energy conversion

Conversion of fuel energy into usable cellular energy

What is metabolism

All cellular chemical reactions that extract usable energy from fuels

What is cellular respiration

A series of chemical oxidations and electron transfers, not always requiring oxygen

Why is ATP considered the cellular energy currency

It stores and transfers energy in a universally usable form

What is the molecular structure of ATP

Adenine + ribose + three phosphate groups

What molecules make up the adenosine phosphate pool

AMP, ADP, and ATP

What type of bond stores energy in ATP

High-energy phosphoanhydride bonds

How much energy is released by breaking a phosphoanhydride bond

7 kcal/mol

How much usable energy is stored in ATP or GTP terminal phosphate bonds

7 kcal/mol

How does ATP couple cellular reactions

Exergonic reactions drive ATP synthesis. ATP hydrolysis powers endergonic reactions

What happens to ATP concentrations as cellular work increases

ATP use rate increases, but ATP remains nearly constant

What enzyme catalyzes ATP regeneration from phosphocreatine

Creatine kinase

What is the ATP regeneration reaction using phosphocreatine

Creatine phosphate + ADP → Creatine + ATP

How much energy does phosphocreatine release

10 kcal/mol

Why is phosphocreatine effective for energy coupling

It donates more energy than ATP hydrolysis requires