Topic 6

Question 1

autotrophs

Answer 1

Plants, algae, and some bacteria are able to harvest the energy of sunlight through photosynthesis, by converting radiant energy into chemical energy.

Question 2

heterotrophs

Answer 2

all other organisms that live on the organic compounds autotrophs produce as food. About 95% of variety of organisms on Earth, animals, fungi, and most protists and prokaryotes are heterotrophs

Question 3

cellular respiration

Answer 3

All organism use cellular respiration to extract energy (ATP) from organic molecules.

is a series of reactions, by which energy is harvested in the oxidation of organic compounds to extract energy from chemical bonds.

The process of cellular respiration, high-energy electrons from the initial chemical bonds have lost much of their energy, and these depleted electrons are transferred to a final electron acceptor.

Question 4

aerobic respiration

Answer 4

is when the final electron acceptor is oxygen.

NADH must be recycled, for glycolysis to continue, either by Aerobic respiration, or fermentation depending on the availability of oxygen.

Question 5

anaerobic respiration

Answer 5

• is when the final electron acceptor is inorganic molecule (CO2 or ethanol)

is a form of cellular oxidation without O2

Question 6

oxidized

Answer 6

involves losing electrons & increasing oxidation number

involves losing a hydrogen for a given compound

releases energy

Question 7

reduced

Answer 7

involves gaining electrons and decreasing oxidation number

involves gaining a hydrogen for a given compound

stores energy

Question 8

dehydrogenation

Answer 8

involves the removal of a hydrogen atom (occurs during energy metabolism)

Question 9

fermentation

Answer 9

is when the final electron acceptor is an organic molecule.

NADH must be recycled, for glycolysis to continue, either by Aerobic respiration, or fermentation depending on the availability of oxygen

Reduces organic molecules in order to regenerate NAD+

it is a form of cellular oxidation without O2

Ethanol fermentation occurs in yeast (CO2, ethanol, and NAD+ are produced
Lactic acid formation – occurs in animal cells (especially muscles), electrons are transferred from NADH to pyruvate to produce lactic acid.

Question 10

ATP synthase

Answer 10

ATP synthase uses energy from a proton gradient in Electron transport chain during oxidative phosphorylation

Most protons can only reenter the matrix though ATP synthase

Question 11

oxidative phophorylation

Answer 11

ATP synthase uses energy from a proton gradient in Electron transport chain.

Question 12

glycolysis

Answer 12

Every cell is capable of glycolysis even if the don’t have a mitochondria so they can still utilize glucose and convert it to ATP.

Glycolysis occurs in the cytoplasm. This is why cells without a mitochondria can perform glycolysis.

Substrate-level phosphorylation – transfers of phosphate groups directly to ADP during glycolysis

it is the first step in cellular respiration (the oxidation of glucose)

Converts 1 glucose (6 carbons) to 2 pyruvate (3 carbons)

10-step biochemical pathway

Net production of 2 ATP molecules by substrate-level phosphorylation

2 NADH produced by the reduction of NAD+

NADH must be recycled to NAD+, for glycolysis to continue, either by Aerobic respiration, or fermentation depending on the availability of oxygen

Question 13

electron transport chain

Answer 13

electron transport chain occurs in the mitochondria.

Oxidative phosphorylation – ATP synthase uses energy from a proton gradient in Electron transport chain

4th step of cellular respiration (oxidation of glucose)

The Electron Transport chain is a series of membrane-bound electron carriers, that are embedded in the inner mitochondrial membrane

Electrons from NADH and FADH2 are transferred to complexes of the ETC

Each complex – is essentially a proton pump creating a proton gradient, and allowing electrons to be transferred to the next carrier, until oxygen being the final acceptor.

Accumulation of protons in the intermembrane space drives protons into the matrix via diffusion

Membrane relatively impermeable to ions

Most protons can only reenter the matrix though ATP synthase

Uses energy of gradient to make ATP from ADP + Pi

Question 14

Understand the processes of Glycolysis and the Krebs cycle

Answer 14

Use the powerpoint since both are lengthy processes MAK SURE TO LEAR THE REACTANTS AND PRODUCTS

Question 15

Identify and understand the variation in energy produced with Aerobic and Anaerobic respiration, and where they are occurring cellularly

Answer 15

Aerobic Respiration

Where it occurs: Aerobic respiration takes place in the mitochondria of the cell.

Energy produced: Aerobic respiration is a highly efficient process that can produce up to 38 ATP molecules from one glucose molecule. However, some sources suggest a yield of about 30 to 36 ATP molecules due to losses in the process.

Requirement: This process requires oxygen

Anaerobic Respiration

Where it occurs: Anaerobic respiration typically takes place in the cytoplasm of the cell.

Energy produced: Anaerobic respiration yields much less energy compared to aerobic respiration. It produces only about 2 ATP molecules per glucose molecule.

Requirement: This process does not require oxygen and occurs when oxygen is absent or in short supply.

Question 16

What is the net production of ATP via glycolysis?

Answer 16

2 ATP

Question 17

Glycolysis produces ATP by which means?

Answer 17

substrate-level phosphorylation

Question 18

ATP synthases uses energy directly for what source to produce ATP?

Answer 18

A proton gradient

Question 19

autotrophs are organisms that?

Answer 19

convert energy from sunlight into chemical energy

Question 20

which of the following is NOT a product of glycolysis?

Answer 20

CO2

Question 21

What process of cellular respiration uses the electrons carried by NADH and FADH2?

Answer 21

Moved between proteins in the inner membrane of the mitochondria to pump protons

Question 22

What is the order of the complete oxidation of glucose?

Answer 22

glycolysis, pyruvate oxidation, krebs cycle

Question 23

Anaerobic respiration occurs in humans due to an absence of what?

Answer 23

O2

Question 24

Where does glycolysis occur in a cell?

Answer 24

in the cytoplasm

Question 25

What is the function of NAD+ in the process of cellular respiration?

Answer 25

Acts as the main electron carrier

Question 26

Define and compare the differences between Autotrophs, and Heterotrophs, in how they obtain energy

Answer 26

Autotrophs – Plants, algae, and some bacteria are able to harvest the energy of sunlight through photosynthesis, by converting radiant energy into chemical energy.

Heterotrophs – all other organisms that live on the organic compounds autotrophs produce as food. About 95% of variety of organisms on Earth, animals, fungi, and most protists and prokaryotes are heterotrophs.

All organism use cellular respiration to extract energy (ATP) from organic molecules.

Question 27

List the overall processes in the complete oxidation of Glucose, listing the four main steps showing the main reactant and products for each step (Glycolysis, Pyruvate oxidation, Krebs cycle, Electron transport chain and Chemiosmosis), and how many ATP and electron carriers are reduced and any other products being produced like CO2.

Answer 27

Glycolysis

Reactant: Glucose
Products: 2 Pyruvate, 2 ATP, and 2 NADH
Location: Cytoplasm

Pyruvate Oxidation

Reactant: Pyruvate
Products: Acetyl CoA, NADH, and CO2
Location: Mitochondrial matrix

Krebs Cycle (Citric Acid Cycle)

Reactant: Acetyl CoA
Products: 2 CO2, 3 NADH, 1 FADH2, and 1 ATP (per cycle)
Location: Mitochondrial matrix

Electron Transport Chain and Chemiosmosis (Oxidative Phosphorylation)

Reactants: NADH, FADH2, O2
Products: ATP, H2O
Location: Inner mitochondrial membrane

Each glucose molecule is broken down into two pyruvate molecules during glycolysis, so each of the subsequent steps (pyruvate oxidation, Krebs cycle, and electron transport chain) occurs twice per glucose molecule. Therefore, the total ATP yield from the complete oxidation of one glucose molecule is about 30 to 36 ATP molecules. This includes 4 ATP molecules produced directly in glycolysis and the Krebs cycle, and approximately 26 to 32 ATP molecules produced in the electron transport chain.

Question 28

Define and understand the differences between Aerobic, Anaerobic and Fermentation oxidation of organic compounds.

Answer 28

Aerobic Respiration – is when the final electron acceptor is oxygen.

Anaerobic Respiration - is when the final electron acceptor is inorganic molecule (CO2 or ethanol)

Fermentation - is when the final electron acceptor is an organic molecule.

Question 29

List and define the oxidation of the other organic macromolecules, like proteins and lipids.

Answer 29

Catabolism of Fat

Fats are broken down to fatty acids and glycerol

Fatty acids are converted to acetyl groups by b-oxidation, which is oxygen-dependent process.

The respiration of a 6-carbon fatty acid yields 20% more energy than 6-carbon glucose

Catabolism of Protein

Proteins are first broken down into their individual amino acids.

The nitrogen-containing side group is then removed from each amino acid in a process called deamination.

A series of reactions then converts the carbon chain that remains into a molecules that enters glycolysis or the Krebs cycle.