Respiration

Question 1

the need for cellular respiration

To include examples of why plants, animals and
microorganisms need to respire (suitable examples
could include active transport and an outline of
named metabolic reactions).

Answer 1

factors are dependednt on metabolic reactions taking place in cells
* grow
* respind to changes in the environment
* find/make food
* reproduce

more specific examples
* active transparent - uptake of nitrates in root hair cells, selective reabsorbtion of glucose and amino acids in the kideny, conduction of nerve cells
* anabolic reactions- building of poly ers like protein polysacharides
* movemnt- brought about by cilia , flagella, contractile filaments in muscle cells

Question 2

define

respiration

Answer 2

is the process by which organic molecules such as glucose are broken down into smaller inorganic molecules like co2 and h20

Question 3

define

anabolism

Answer 3

the synthesis of complex molecules in living organisms from simpler ones together with the storage of energy; constructive metabolism.

Question 4

recall the

equation of respiration

Answer 4

C6H12O6 + 6O2->6CO2+6H20

Question 5

energy can only be

Answer 5

released or absorbed- never lost, produced, made, created

Question 6

what is respiration

not define

Answer 6

Respiration is a series of reactions that convert chemical energy stored in carbohydrates into ATP. It takes place in the mitochondria of eukaryotic cells. Its the processes that converts energy within the bonds of glucose into a more readily available form ; ATP

Question 7

explain the differences between

aerobic and anerobic respiration

Answer 7

aerobic:
- reactions and products are the same in plants, animals, yeast
- water is produced
- more atp is produced
- glucose is fully broken down
- it has more steps post glycolis aka link reaction, krebs, oxidative phosphorylation
anerobic
- two types:ethanal fermentation in plants and yeast or lactate fermentation in animals

Question 8

what are the 2 steps of

respitation

Answer 8

1. phosphorlyation
   * phosphorylation of glucose to hexose biphosphate the two phosphates are released frpm two atp molecules
   * lysis- hexose biphosphate then splits into two molecules of triosphosphate because its been destabalised
   * another phosphate group (this time from free inorganic Pi present in cytoplasm) to form triose biphosphate
2. oxidation
   * dehydrogentation- the two triose phosphate molucles are oxidised to pyravate by the removal of hydrogen each producing a molecule of reduced nad (nadh)
   * formation each trios biphosphate produces two molecules of atp

Question 9

whats the net gain at glyclolsyss

Answer 9

2 atp molecues (4 but you used two fpr initail phosphorylation) and 2 nadh

Question 10

where does

glycolysis take place?

Answer 10

in cell cytoplasm

Question 11

what is

substrate phosphorylation

Answer 11

when ATP is synthesised without ETC. Instead its synthesied by the transfer of phosphate groups from a phosphorylated intermediate to adp

Question 12

is glycolysis

anerobic or aerobic

Answer 12

anerobic

1st stage in both

Question 13

what happens to nadh formed at glycolysis

Answer 13

go to oxidative phosphorlyation

Question 14

what are the three title for oxygen dependince in organisms

Answer 14

• obligate anerobes
• faculative anerobes
• obligate aerobes

Question 15

give a description and example

of the oxygen dependence

Answer 15

1. obligate anerobes - cannot survive in the presence of 02, almost all prokaryotes and some fungi
2. faculative anerobes - can switch to anerobic eg yeast
3. obligate aerobes - eg. mamals require o2 to synethesis atp

Question 16

what is

fermentation

Answer 16

is the process by which complex organic compounds are broken down into simpler inorganic compounds without the use of oxygen or involvmet of the etc

atp syntheised by substrate phosphorylation only

Question 17

the end product of fermentation in yeast and some plant root cells is …

Answer 17

ethanol and co2

Question 18

the end product of fermentaion in animal cells is….

Answer 18

lactate

Question 19

why does the lack of oxygen

prevent aerobic respiration

Answer 19

when there is no 02 to act as the final electron acceptor at the end of the etc in oxidative phosphorylation the flow of electrons stops. this means synthesis of atp by chemiosmosis stops and reduced NAD and reduced FAD are no longer available to be oxidised beacuse there is no where for the elecrtrons to go. so nad and fad cannnot regenerate and so decarboxylation and oxidation of pyravate and the krebs cycle come to a hault as there is no coenzyme available to accept the hydrogens being removed. Glycolysis would also hault if not fore the process of fermentation.

Question 20

sketch out the proces

of alcohol fermentation

Answer 20

see notes

Question 21

sketch out the processes

of lactate fermentation

Answer 21

see notes

Question 22

can alcohol fermentation conrinue indefitley and why?

Answer 22

yes its not only a short term however ethanol is toxic so conc above 15% accumilating kills yeast cells

Question 23

can lactate fermentation conrinue indefitley and why?

Answer 23

no becuase not enough ATP produced to maintain vital processes for long period of time and accumilation of lactic acid is acidic denaturinf respiration enzymes

Question 24

what is the process of anerobic respiration

Answer 24

to reoxidise nadh to NAD so glycolisi can continue

Question 25

is the two types of anerobic respiration reversible and why??

Answer 25

lactate fermentation yes beacuse lactate is broken down again into glucose in the liver however that process requires oxygen

alcohol fermentation is irreversible beacuse a carbon is lost

Question 26

which makes more atp and why

anerobic or aerobic

Answer 26

anerobic makes less atp beacuse only one atp producing stage: glycolysis only 2 atp per glucose

Question 27

which respiritoty substrate releases most energy

Answer 27

loipids, protein, carbs beacuse higher proportion of H atoms per mass can reduce most NAD’FAD so more atp generated

Question 28

link reaction happens

where?

Answer 28

mitocondrial matrix

Question 29

what is the first step of the

link reaction

Answer 29

decarboxylated and dehydrogenayed to acetate

Question 30

sketch the process of the

link reaction

Answer 30

see notes

Question 31

link reaction also known as

Answer 31

oxidative decarboxylation

Question 32

acetate in link reaction combinds with ….to produce

Answer 32

coenzyme a to form acetyl coenzyme A

Question 33

net gain of

link reaction

Answer 33

1 co2
1nadh