Ch 9 Bio MO2A

function of respiration

the process by which organisms take in oxygen from their environment, use it to break down food molecules (like glucose) within their cells to generate energy (ATP), and release carbon dioxide as a waste productfunction of respiration

aerobic respiration

a biological process where cells convert glucose (sugar) into energy (ATP) in the presence of oxygen, producing carbon dioxide and water as byproducts

anaerobic respiration

a metabolic process where cells generate energy (ATP) without the presence of oxygen, utilizing alternative electron acceptors instead of oxygen to break down glucose and produce a smaller amount of energy compared to aerobic respiration

relation between respiration and fermentation

Respiration and fermentation are both processes used by organisms to generate energy from glucose, but the key difference is that respiration requires oxygen while fermentation does not

advantage of controlled release of energy in cellular respiration

it allows the cell to efficiently capture a much larger proportion of the energy available from a glucose molecule as usable ATP, rather than losing most of it as heat

substrate level phosphorylation

a metabolic process where ATP is generated by directly transferring a high-energy phosphate group from a phosphorylated intermediate molecule (the "substrate") to ADP, producing ATP

different energy conversions involved in respiration

primary energy conversion is from chemical potential energy stored in glucose molecules to the usable chemical energy stored in ATP (adenosine triphosphate)

oxidation

a chemical reaction where a molecule loses electrons, often associated with the gain of oxygen or loss of hydrogen atoms

Reduction

a chemical reaction where a molecule gains electrons, meaning its oxidation state decreases

NAD+

oxidized

a molecule that plays a vital role in cell viability and metabolism

NADH

reduced

NADH is a reducing agent that donates electrons to other molecules. It's involved in many cellular processes

FAD

oxidized

a coenzyme that's involved in many enzymatic reactions and redox processes

FADH2

reduced

a redox cofactor that plays a key role in cellular respiration

dehydrogenase

enzymes that catalyze oxidation reduction reactions ,enzymes that play a role in many biological processes

phosphorylation

the process of adding a phosphate group (PO3-) to a molecule, most commonly a protein

isomerization

the process where a molecule changes its structure to become a different isomer

Oxidation reduction

a chemical reaction where electrons are transferred between molecules, with one molecule losing electrons (oxidized) and another molecule gaining those electrons (reduced)

What are the substrates of glycolysis?

glucose and ATP

What are the products of glycolysis?

two molecules of pyruvate, two molecules of ATP, and two molecules of NADH

How many net ATP are formed

two molecules per glucose molecule

oxidation of pyruvate to acetyl CoA

a pyruvate molecule (a 3-carbon compound) is converted into acetyl CoA (a 2-carbon compound attached to coenzyme A) by losing one carbon atom as carbon dioxide, while simultaneously transferring electrons to NAD+ to produce NADH; this process occurs in the mitochondrial matrix and is essential for feeding the acetyl group into the citric acid cycle (Krebs cycle) to generate further energy in the form of ATP

Substrates of citric acid cycle

acetyl-CoA and oxaloacetate

Product of citric acid cycle

carbon dioxide (CO2), NADH, FADH2, and ATP

how many nadh are produced in citric acid cycle

three NADH molecules

How many FADH2 are produced in citric acid cycle

two molecules of FADH2 for each glucose molecule that is broken down

how many atp are produced in citric acid cycle

two ATP molecules per cycle

What waste product is produced in citric acid cycle

carbon dioxide (CO2

why is citric acid cycle considered a cycle

the final product of the reaction sequence, oxaloacetate, is used as a reactant in the first step, allowing the cycle to begin again with a new acetyl-CoA molecule, essentially creating a continuous loop of reactions

What is the role of NADH and FADH in electron transport

NADH and FADH2 act as electron carriers in the electron transport chain, transferring high-energy electrons obtained from the breakdown of glucose during glycolysis and the Krebs cycle to the electron transport chain

Where are complexes I-IV located in electron transport

within the inner mitochondrial membrane of eukaryotic cells

What type of gradient is established as a result of electron transport chain?

proton gradient

role of O2

acts as the final electron acceptor

What are the final products in electron transport and chemiosmosis

water (H2O) and ATP

chemiosis

the movement of ions, typically hydrogen ions (protons), across a semipermeable membrane down their electrochemical gradient

ATP synthetase

generates ATP by utilizing the energy stored in a proton gradient across a cell membrane; protons flow through the enzyme complex, driving a conformational change that allows the binding of ADP and inorganic phosphate to form ATP, essentially converting potential energy from the gradient into chemical energy stored in ATP molecules

ATP Yield

2 ATP produced during glycolysis, 2 ATP during the citric acid cycle, and the majority (around 28-30 ATP) generated during the electron transport chain and chemiosmosis stage

When does anaerobic respiration occur?

when there is a lack of oxygen available for a cell to perform its normal aerobic respiration

Why is anaerobic respiration needed

to provide a quick burst of energy to organisms when oxygen is limited

What product is formed during anaerobic respiration in yeast?

ethanol (alcohol) and carbon dioxide

What product is formed during anaerobic respiration in humans?

lactic acid

Describe the benefit and disadvantages of anaerobic respiration.

benefit: Allows for rapid ATP production without oxygen, crucial for short bursts of high-energy activity

disadvantage: Generates much less ATP per glucose molecule compared to aerobic respiration

Describe the effect of AMP on phosphofructokinase

acts as a positive allosteric effector on phosphofructokinase, meaning it activates the enzyme

Describe the effect of ATP on phosphofructokinase

ATP acts as an allosteric inhibitor of phosphofructokinase, meaning that when ATP levels are high, it binds to a regulatory site on the enzyme and decreases its activity

Describe the effect of citrate on phophofructokinase

Citrate acts as a potent inhibitor of phosphofructokinase, meaning it significantly decreases the activity of this enzyme, effectively slowing down the glycolysis pathway by preventing the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate

Describe how fats and amino acids feed into cellular respiration.

being broken down into smaller molecules that can then join the existing metabolic pathways