Cellular Respiration

Question 1

Definition of cellular respiration

Answer 1

Cellular respiration is the chemical process where glucose is broken down gradually,
in the presence of oxygen (aerobic respiration) or in the absence of oxygen
(anaerobic respiration), to release energy.

Question 2

metabolism

Answer 2

chemical processes in organisms which are controlled by enzymes

Question 3

catabolic

Answer 3

a metabolic process in which complex molecules are broken down
into simple ones to release energy

Question 4

anabolic

Answer 4

the synthesis of more complex substances from simple molecules

Question 5

Importance of energy

Answer 5

 growth
 cell division
 movement
 transport of substances
 active transport

Question 6

aerobic respiration

Answer 6

respiration in the presence of oxygen

Question 7

mitochondrion

Answer 7

organelle / site for respiration

Question 8

ATP

Answer 8

general energy carrier molecule in cells

Question 9

Aerobic respiration takes place:

Answer 9

 in the presence of oxygen;
 inside the cytoplasm and mitochondria of cells.

Question 10

Aerobic respiration takes place in three stages:

Answer 10

1. Glycolysis – takes place in the cytoplasm
2. Krebs Cycle – takes place inside the mitochondrion
3. Oxidative Phosphorylation – takes place inside the mitochondrion

Question 11

Glycolysis

Answer 11

 takes place outside the mitochondrion, in the cytoplasm of the cell
 no oxygen is required during this stage
 glucose is broken down into smaller molecules, releasing a small amount of
energy that is stored in energy-rich ATP molecules
 releases high energy hydrogen ions (H+
) that are used in the third stage of
cellular respiration (oxidative phosphorylation)

Question 12

Krebs Cycle

Answer 12

 can only take place if oxygen is present
 occurs inside of the mitochondrion
 releases carbon dioxide and high energy hydrogen ions (H+
)
 transports hydrogen atoms to the third stage (oxidative phosphorylation) via
hydrogen carrier enzymes

Question 13

Oxidative Phosphorylation

Answer 13

 takes place inside of the mitochondrion and requires oxygen
 passes high energy hydrogen atoms from one hydrogen carrier enzyme to the
next, releasing energy in the process
 uses released energy to combine a phosphate molecule to an ADP
(Adenosine Di-phosphate) molecule to form ATP – called phosphorylation
 is represented in the formula: ADP + P ATP
 oxygen acts as a final hydrogen acceptor binding with the hydrogen forming
water which is released as a waste product of cellular respiration

Question 14

anaerobic respiration

Answer 14

respiration in absence of oxygen

Question 15

fermentation

Answer 15

type of anaerobic respiration in yeast (and other) cells

Question 16

alcoholic fermentation

Answer 16

breaking down of glucose in absence of oxygen, to
give rise to the production of alcohol in plant cells

Question 17

lactic acid fermentation

Answer 17

breaking down of glucose in absence of oxygen to
form lactic acid in animal cells

Question 18

lactic acid

Answer 18

acid formed in muscle cells, during anaerobic
respiration; leads to muscle exhaustion / cramping