Cellular Respiration 2.6 U2

Question 1

What is cellular respiration?

Answer 1

Process that cells use to release energy by breaking down glucose and other food molecules
Composed of three main parts
Most parts of cellular respiration require oxygen (which is why we need to breathe!)
“Respiration”
ALL cells must carry out some version of cellular respiration to have energy to live!
Cells that live in anaerobic environments can only do the anaerobic parts!

Question 2

What is aerobic?

Answer 2

requires oxygen

Question 3

What is anaerobic?

Answer 3

does not require oxygen

Question 4

What are the three stages of cellular respiration and are they anaerobic or aerobic?

Answer 4

Glycolysis
Anaerobic
Krebs Cycle
Aerobic
Electron Transport Chain
Aerobic

Question 5

What is glycolysis?

Answer 5

“Sugar-breaking”
Molecule of glucose is broken down into two molecules of pyruvic acid
Glucose = 6 carbons
Pyruvic acid (also called pyruvate) = 3 carbons
Needs 2 ATP for the process to begin, and produces 4 ATP
NET GAIN OF 2 ATP PER GLUCOSE MOLECULE
Also produces 2 NADH molecules
Passes 4 high energy electrons to NAD+
NADH is used later in the electron transport chain
Occurs in the cytoplasm
Anaerobic
Does NOT require oxygen

Question 6

What is glucose broken into

Answer 6

Molecule of glucose is broken down into two molecules of pyruvic acid

Question 7

Does glycolysis require oxygen?

Answer 7

Does NOT require oxygen
Anaerobic

Question 8

Where does glycolysis occur

Answer 8

Occurs in the cytoplasm

Question 9

How much ATP does glycolysis produce?

Answer 9

Needs 2 ATP for the process to begin, and produces 4 ATP
Net 2 ATP

Question 10

How much NADH molecules does glycolysis produce?

Answer 10

Also produces 2 NADH molecules
Passes 4 high energy electrons to NAD+
NADH is used later in the electron transport chain

Question 11

What are electron carriers?

Answer 11

Allow a cell to move electrons around as needed

Question 12

What are the electron carriers involved in cellular respiration?

Answer 12

Ex. in cellular respiration: NADH and FADH2

Question 13

Where is the mitochondria found?

Answer 13

Found in cytosol of the cell

Question 14

What is a cristae?

Answer 14

Inner membrane has cristae (many inward protrusions)
Increases surface area!

Question 15

What is intermembrane space?

Answer 15

space between double membranes

Question 16

What is the mitochondrial matrix?

Answer 16

compartment within inner membrane

Question 17

Why is the multi-compartment structure important for the mitochondria?

Answer 17

helps keep reactions separate and maintain different molecule concentrations in certain areas

Question 18

What is the Krebs Cycle(Citric Acid Cycle)

Answer 18

Pyruvate enters the mitochondria
Pyruvate is first converted to acetyl-CoA in order to prepare for the cycle
This conversion produces 1 NADH and 1 molecule of CO2
Occurs in mitochondrial matrix
Acetyl-CoA (generated from pyruvic acid) is broken down into carbon dioxide in a series of energy-extracting reactions
Cycle turns twice per original glucose molecule
1 glucose = 2 pyruvate
Each turn of cycle = 1 ATP produced
Per glucose = 2 ATP produced
Aerobic, occurs in matrix

Question 19

What is pyruvate turned into before krebs cycle?

Answer 19

Pyruvate is first converted to acetyl-CoA in order to prepare for the cycle

Question 20

Where does the krebs cycle occur?

Answer 20

Occurs in mitochondrial matrix

Question 21

How much NADH does the krebs cycle produce?

Answer 21

6 NADH

Question 22

How much CO2 does the krebs cycle produce?

Answer 22

4 CO2

Question 23

How much ATP does the krebs cycle produce?

Answer 23

2ATP

Question 24

How much FADH does the krebs cycle produce?

Answer 24

2 FADH

Question 25

What is the Electron Transport Chain(ETC)?

Answer 25

Series of electron carrier proteins that shuttle high-energy electrons during ATP-generating reactions
Oxidative Phosphorylation
Electron carriers were made in glycolysis & Krebs cycle
NADH and FADH2
ATP Synthase = generates ATP from ADP
Occurs in inner mitochondrial membrane
Regenerates electron carriers
Generates electrochemical gradient

Question 26

What does ETC produce? How Much?

Answer 26

Produces water and ~32 ATP

Question 27

What is ATP Synthase?

Answer 27

generates ATP from ADP
Works similarly to a water turbine in a power plant
H+ ions instead of water

Process is called chemiosmosis

Question 28

Where does ETC occur?

Answer 28

Occurs in inner mitochondrial membrane

Question 29

Where are electron carriers made that are used in ETC?

Answer 29

Electron carriers were made in glycolysis & Krebs cycle

Question 30

What is chemiosmosis?

Answer 30

Energy stored in proton gradient used to do work

Question 31

What is the chemical equation for cellular respiration?

Answer 31

C6H12O6 + 6O2 —> 6CO2 + 6H2O + ATP

Question 32

What is anaerobic respiration?

Answer 32

Anaerobic Steps:
Glycolysis
Fermentation
Lactic Acid
Ethanol/Alcohol

Question 33

Where does anaerobic respiration occur?

Answer 33

Cytoplasm

Question 34

What is the goal of fermentation?

Answer 34

Allows you to continue to conduct glycolysis to generate those 2 ATP over and over again!
Steady supply of ATP

Nowhere near as much energy as aerobic respiration, but better than nothing!

Question 35

What are the types of fermentation?

Answer 35

Alcohol Fermentation and Lactic Acid Fermentation

Question 36

What is Alcoholic Fermentation?

Answer 36

Produces CO2 and Ethanol/Alcohol and NADH
Pyruvic acid + NADH —> Alcohol + CO2 + NAD+

Question 37

hat is Lactic Acid Fermentation?

Answer 37

Produces Lactate and NADH
Pyruvic acid + NADH —> Lactic acid + NAD+

Question 38

What are common uses for alcoholic fermentation?

Answer 38

Used to produce alcoholic drinks and biofuel
Process that causes bread to rise

Question 39

What are common uses for Lactic Acid fermentation?

Answer 39

Food processing and preservation, such as pickles, sauerkraut, kimchi, yogurt, cured fish/meats
Quick bursts of energy for humans! (<90 s)