Biology Unit 3 Topic 6 & 7: Cellular Respiration & Fitness

cellular respiration

cellular process breaking down starch into glucose, transferring electrons to lower energy, releasing energy to use in ATP synthesis

oxidation

the complete or partial loss of electrons

reduction

the complete or partial gain of electrons

NAD+

coenzyme electron carrier accepting high-energy electrons from Glycolysis → reducing to NADH

transporting electrons to ETC → generating a proton gradient to make ATP

FADH

coenzyme electron carrier that picks up high-energy electrons during Citric Acid Cycle → delivers to ETC

generating a proton gradient that powers ATP synthesis

glycolysis

starting point of cellular respiration occurring in the cytosol

splitting glucose into 2 pyruvates

ATP synthase

enzyme in inner mitochondrial membrane

makes ATP from ADP + P

uses energy from proton gradient as H+ flow down

a rotor spinning when H+ binds to it → activating catalytic sites to synthesize 26-28 ATP per 1 glucose molecule

Anaerobic respiration

process takes place in prokaryotic organism

generates ATP using ETC in absence of oxygen

final electron acceptors; sulfates or nitrates

fermentation

process that is an extension of glycolysis occurring in cytosol

ATP is generated w/o ETC by recycling NAD+

What is the overall reaction of cellular respiration?

Organic molecules + oxygen  CO2 + H2O + energy

How does oxidation and reduction play a role in cellular respiration?

oxidation-transfers electrons to a lower energy state, releasing energy to use in ATP synthesis

reduction-NAD+ and FAD gains those lost electrons to become NADH and FADH2, delivering electrons to ETC to generate ATP

What steps of glycolysis require energy?

energy investment stage -cell uses ATP to phosphorylate compounds of glucose

What steps of glycolysis release energy?

energy payoff stage-energy is produced through substrate level phosphorylation → yielding 2 ATP molecules and 2 NADH molecules

How is ATP synthesized in glycolysis?

substrate level phosphorylation- 2 ATP phosphorylate glucose and they are converted into pyruvate through reactions that generate ATP and NADH

What happens to the pyruvate that is produced via glycolysis?

it is oxidized into acetyl CoA when oxygen is present → 2 CO2 and 2 NADH produced

What is the purpose of the citric acid cycle?

turn acetyl CoA into citrate → releasing CO2, synthesizing ATP, transferring electrons to NADH and FADH2 to power ETC

Critically think: why do fats store more energy than carbohydrates? Go back to the Mighty Mouse video/reading and your Unit 1 packet to help.

they require more energy and oxygen to perform activities as they have more covalent bonds (C-H)

What happens to muscle cells if they deplete their supply of oxygen and ATP?

go through lactic acid fermentation to produce ATP

causes burning sensation when performing strenuous exercise

Describe step-by-step what would happen if oxygen was removed from the ETC.

not present as final electron acceptor → no water made and no electrons moving down ETC → no proton gradient made, no chemiosmosis and cellular work powered

would go under fermentation to produce ATP instead

How does fermentation produce alcohol?

converting 2 pyruvate molecules from glycolysis into 2 ethanol molecules

How does fermentation produce lactic acid?

reducing 2 pyruvate molecules from glycolysis w/ NADH to form lactate

Justify this statement, “Cells make ATP by oxidative phosphorylation.”

do this by oxidizing acetyl CoA, turned into citrate, synthesizing ATP through proton gradient

True or False: plants do not go through cellular respiration.

false - plants require ATP to perform cellular activities and make oxygen

Compare the Golgi Complex to a warehouse/mail facility. How is its function similar?

Receives vesicles from the ER (similar to mail and packages they receives)

Then they modify, sort, add molecular tags, and package them into new transport vehicles to be sent to different locations (like how they sort and send out their packages)

What is the difference in how much ATP can be produced through aerobic respiration vs anaerobic respiration and fermentation?

aerobic-30-32 ATP

anaerobic-2 ATP

Why does oxygen play such an important role in cellular respiration (hint: think about the ETC).

final acceptor of falling electrons in ETC → creating proton gradient to power ATP synthesis

function of photosynthesis vs cellular respiration

photosynthesis-captures light energy through pigments and stores it in G3P molecules

cellular respiration-releases ATP energy that was stored in sugars

location of photosynthesis vs cellular respiration

photosynthesis-light reactions in thylakoid of chloroplast and calvin cycle in stroma of the chloroplast

cellular respiration-glycolysis in cytosol, pyruvate oxidation in mitochondria, citric acid cycle in mitochondrial matrix, ETC in inner membrane of mitochondria, chemiosmosis in inner mitochondrial membrane for eukaryotes and plasma membrane for prokaryotes

reactants for photosynthesis vs cellular respiration

photosynthesis-water and CO2

cellular respiration-O2 and glucose

products for photosynthesis vs cellular respiration

photosynthesis-O2 and Glucose

cellular respiration-H2O and CO2

overall reaction for photosynthesis vs cellular respiration

photosynthesis-6CO2 + 6H2O + light energy → C6H12O6 + 6O2

cellular respiration-Organic molecules + oxygen → CO2 + H2O + energy

type of cell for photosynthesis vs cellular respiration

photosynthesis-plant cells

cellular respiration-plant and animal cells

Think back to the Mighty Mouse activity. How were the deer mice adapted to their surroundings?

changing hemoglobin for characteristics of environment

highlander mice had better hemoglobin bc of low level of oxygen in environment and their burning of fats → better binding to oxygen so blood can transport more oxygen to tissues

How do adaptations come about?

an organism makes changes to their body over time through natural selection → lower mortality rate → eventually whole population has these more desirable traits

Do organisms try to adapt? (i.e. does a bug try to turn different colors to camouflage in its environment?)

yes - adaptation is crucial to survival

if they could not adapt - many species would cease to exist