cellular respiration

Question 1

define respiration

Answer 1

breaking down of organic compounds (glucose) with the gradual release of energy that is stored in ATP molecules

Question 2

metabolism

Answer 2

chemical processes in organisms which are controlled by enzymes

Question 3

what are the 5 imp of energy

Answer 3

1- growth
2- cell division
3- movement
4- transport of substances
5- active transport

Question 4

aerobic respiration

Answer 4

respiration in the presence of oxygen

Question 5

mitochondrion

Answer 5

organelle / site for respiration

Question 6

ATP

Answer 6

general energy carrier molecule in cells (adenosine triphosphate)

Question 7

4 adaptations of mitochondrion

Answer 7

1- outer membrane is smooth= easy movement of mitochondrion through cytoplasm

2- outer membrane is selectively permeable= permeable to O2 and pyruvic acid (req for last 2 phases of cellular respiration)

3- inner membrane is highly folded= form cristae, incre SA for enzyme attachment

4- lumen/ matrix contain DNA + ribosomes= for making (synthesis) of enzymes req for cellular respiration

Question 8

what are the 3 stages of aerobic respiration and where do they take place

Answer 8

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

Question 9

Glycolysis (4)

Answer 9

1- takes place outside the mitochondrion, in the cytoplasm of the cell

2- no oxygen is required during this stage

3- glucose is broken down into smaller molecules, releasing a small amount of
energy that is stored in energy-rich ATP molecules

4- releases high energy hydrogen ions (H+) that are used in the third stage of
cellular respiration (oxidative phosphorylation)

5- 2 pyruvic acid molecules, 3 carbon atoms each formed

Question 10

Krebs Cycle (5)

Answer 10

1- can only take place if oxygen is present

2- occurs inside of the mitochondrion

3-releases carbon dioxide and high energy hydrogen ions (H+)

4- transports hydrogen atoms to the third stage (oxidative phosphorylation) via
hydrogen carrier enzymes

5- series of cyclic reactions take place

Question 11

Oxidative Phosphorylation (5)

Answer 11

1- takes place inside of the mitochondrion and requires oxygen

2- passes high energy hydrogen atoms from one hydrogen carrier enzyme to the
next, releasing energy in the process

3- uses released energy to combine a phosphate molecule to an ADP
(Adenosine Di-phosphate) molecule to form ATP – called phosphorylation

4- is represented in the formula: ADP + P ATP

5- oxygen acts as a final hydrogen acceptor binding with the hydrogen forming
water which is released as a waste product of cellular respiration

Question 12

anaerobic respiration

Answer 12

respiration in absence of oxygen

Question 13

fermentation

Answer 13

type of anaerobic respiration in yeast (and other) cells

Question 14

alcoholic fermentation

Answer 14

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

• glycolysis occurs, producing pyruvic acid which in plants during anaerobic resp are broken down further during alcohol fermentation to produce alcohol and CO2

Question 15

lactic acid fermentation

Answer 15

breaking down of glucose in absence of oxygen (anaerobic resp) to
form lactic acid in animal cells.

• glycolysis occurs, producing pyruvic acid which in animals during anaerobic respiration is further broken down during lactic acid fermentation into lactic acid

Question 16

lactic acid

Answer 16

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

toxin that leads to muscle stiffness + muscle pain

Question 17

why/ when does anaerobic respiration occur in humans

Answer 17

occurs: humans: strenous acty, if aerobic respiration is not supplying enough O2 then anaerobic respration occurs to supplement the energy supply. the O2 supply rate to tissue doesn’t match rate of respiration req.

Question 18

what are the products of aerobic respiration

Answer 18

CO2 and H2O

Question 19

what are the products of anaerobic respiration

Answer 19

animal: lactic acid

plant + yeast cell: CO2 and alcohol

Question 20

lime water

Answer 20

solution used to test for carbon dioxide

Question 21

lactic acid bacteria

Answer 21

produce lactic acid via anaerobic resp, used to make cheese and yoghurt, it turns milk sour and reduces its pH

Question 22

renin

Answer 22

enzyme, proteases, used to make cheese, its added to cuddle milk, incre clumping

Question 23

biotechnology

Answer 23

use of living organisms in industrial process

Question 24

anaerobic respiration which occurs in yeast cells

Answer 24

alcoholic fermentation

Question 25

anaerobic respiration which occurs in muscle cells

Answer 25

lactic acid fermentation

Question 26

malted barley

Answer 26

germinating malt grains which are dried and finely chopped in the process of brewing beer

Question 27

describe the beer making process(8)

Answer 27

1- barleycorn soaked in water till it starts germinating

2- this germinating grain is dried and chopped (now called malted barley)

3- malted barley is mixed with warm water, and sugar in barley dissolves .

4- now called wort(sweet, syrupy liquid) is drained

5- hops are added to the wort and boiled (hop: flower gives beer its bitter taste)

6- yeast cells added to the wort - hops mix and left to fermentate

7- yeast converts the sugar to alcohol and CO2 during fermentation (co2 is the bubble )

8- when fermentation done, yeast cells sink to bottom of container, its then filtered out and beer bottled

Question 28

describe the wine making process (7)

Answer 28

1- grapes picked and pressed
2- pulp placed into vat
3- yeast is added
4- fermentation occurs at controlled temp
5- alcohol and CO2 released
6- skins and seeds removed via filtration
7- further fermentation and placed into ageing barrels

Question 29

describe the bread making process (4)

Answer 29

1- dough is made from flour, water

2- yeast is added

3- left in warm place (1 hr), Co2 formed and dough rises (due to co2)

4- bake (alcohol evaporates, yeast cells destroyed by high temp)

Question 30

describe cheese making process (5)

Answer 30

1- lactic acid bacteria added to milk

2- reninin added to cuddle milk

3- curd cut into slabs

4- curd compressed + left to ripen

5- cheese