RESPIRATION

Question 1

Where does aerobic respiration occur?

Answer 1

The mitochondria

Question 2

Aerobic respiration definition & outline

Answer 2

Respiration in the presence of oxygen. Used for long duration. Doesn’t produce lactic acid. Produces (36) ATP, CO2, H2O.

Question 3

Anaerobic respiration definition & outline

Answer 3

Respiration without the presence of oxygen. Used for short duration when a cell’s demand for energy is high and is not able to transport energy quick enough. Produces 2 ATP molecules & lactic acid.

Question 4

Where does anaerobic respiration occur?

Answer 4

In the cytoplasm of a cell

Question 5

Purpose of respiration

Answer 5

Converting stored chemical energy (glucose) (breaking down) into carbon dioxide and water to make ATP molecules which all cells can use.

Question 6

Why do we need ATP?

Answer 6

All living cells need energy to carry out basic life processes and survive. All cells use ATP, a form of energy.

Question 7

What is ATP?

Answer 7

Adenosine Triphosphate. Used to store and release energy for chemical reactions occurring within cells. Made from ADP (Adenosine Diphosphate).

Question 8

What are the 3 steps in Aerobic respiration?

Answer 8

1. Glycosis (occurs in the cytoplasm outside the mitochondria. One glucose molecule is broken down into 2 molecules of pyruvate, & ATP)
2. Krebs Cycle (Pyruvate molecules enter the matrix of the mitochondria and is broken down through a series of reaction to form hydrogen and carbon dioxide)
3. Electron transfer chain (occurs in the cristae, through a series of reactions, the ATP - ADP cycle, produces 36 ATP)

Question 9

ATP - ADP cycle

Answer 9

To trap energy formed in the breakdown of glucose (glycolysis), the cell uses this released energy to attach a high energy phosphate group to the ADP molecule to make ATP. [ A-P-P + P —> A-P-P-(P)]
The bonds between the 3 phosphate groups contain a lot of potential energy, and to release this energy for other cell processes, enzymes remove the third phosphate from ATP forming ADP and inorganic phosphate once again. CYCLE REPEATS. ENERGY ADDED, ENERGY RELEASED.

Question 10

Where glucose required for respiration reactions come from

Answer 10

Food (carbohydrates)

Question 11

How ATP & ADP move into and out of the mitochondria

Answer 11

Facilitated diffusion

Question 12

ATP energy used for processes such as

Answer 12

Active transport, cell division, movement, protein synthesis

Question 13

Aerobic respiration balanced symbol & word equation

Answer 13

C6H12O6 + (6)O2 —-> (6)CO2 + (6)H2O + ATP
glucose + oxygen —> carbon dioxide + water + energy

Question 14

Anaerobic word equation

Answer 14

glucose ——> lactic acid + (2)ATP

Question 15

Cells with high energy requirements (e.g. sperm cells, muscle cells, which undertake active transport) have…

Answer 15

A lot of mitochondria

Question 16

Discussion of the process of aerobic respiration and mitochondria

Answer 16

[purpose, what is needed & what is produced]
Aerobic respiration is a series of enzyme reactions that break down glucose (food) to produce ATP (energy).
Requires glucose and oxygen and produces carbon dioxide, water and ATP through a series of enzyme controlled stages.
[structure + function of mitochondria]
Occurs in the mitochondria which are rod-shaped organelles which are specially adapted to increase energy production efficiency. The rod-shaped structure increases their surface area for the diffusion of oxygen and glucose (in) and carbon dioxide and water (out). They have a double membrane to allow compartmentalisation which means conditions (pH and temp) are optimised. The inner membrane (cristae) is highly folded to increase surface area for reactions (in the respiratory chain) to occur quickly. The fluid-filled space is the matrix which provides a media for reactions like the Krebs cycle to occur.
[Why some cells have lots of mitochondria]
Cells such as sperm & muscle cells have a high number of mitochondria due to having high energy requirements. Sperm cells need to move their flagellum sufficiently to swim long distances and muscle cells need to contract their fibres sufficiently. Therefore these processes require a lot of ATP to complete their functions, which is why they contain a high number of mitochondria.