Bioenergetics

Question 1

what is photosynthesis?

Answer 1

Plants synthesis glucose using light energy from the sun. Light energy is converted into chemical energy

Question 2

where does photosythsis take place?

Answer 2

In the cholorphyll of leaf mainly in the palisade cells

Question 3

Word equation for photosythesis?

Answer 3

carbon dioxide + water = glucose+ oxygen

Question 4

Is photo an endothermic or exothermic reaction?

Answer 4

Endothermic, energy from the sun enters the leaves.

Question 5

(RQ) How can you have shown that the plant gives off oxygen during photosythesis?

Answer 5

Using a water plant like pond grass, and contain the bubbles created by photosythesis in the water. The gas will be able to relight a splint as it contains oxygen

Question 6

Leaf adaptations for maximum photosynthesis is?

Answer 6

Broad leaves = larger surface area
thin leaves = shorter diffusion distance
lots of chlorophyll = ensure’s that the most light energy is trapped
Transport veins = pholem can quickly take the glucose produced away
Air spaces = allows Co2 and O 2 to leave the plant
Guard cells = control the stomata for gas exchange and control water loss

Question 7

What affects the rate of photosynthesis?

Answer 7

Temperature, light intensity, carbon dioxide concentration and chlorophyll amount

Question 8

How does temperature affect it?

Answer 8

Increasing the temperature increases the rate of photosythsis, as it increases the kinetic energy of particles. However the rate increasing past a certain temp will cause enzymes to be denatured

Question 9

How does light affect the rate?

Answer 9

Light will increase the rate of photosythesis until another factor becomes limiting

Question 10

What is a limiting factor?

Answer 10

An environmental factor that restricts the amount of photosythesis

Question 11

How can you calculate the rate of photosythesis by measuring oxygen production? (RQ)

Answer 11

Set up a bubble potmeter apparatus pondweed in a sealed tube of water attached to a capillary tube and a gas syringe
Oxygen gas produced causes the bubble in the capillary tube to move the distance moved by the bubble is used to calculate the amount of oxygen

Question 12

how can farmers use the limiting factors for maximum profit?

Answer 12

They can control temperature (greenhouse) light intensity (artifical lighting) and co2 concentration (paraffin heaters) leading to a greater yield.

Question 13

5 uses of glucose in the plant

Answer 13

for respiration
stored as starch for storage
cellulose for strength
amino acids for protien sythensis
lipids for energy in seeds

Question 14

What is aerobic respiration?

Answer 14

An exothermic reaction in which glucose reacts with oxygen to release energy

Question 15

word equation for aerobic respiration?

Answer 15

Glucose + oxygen = carbon dioxide + water + (energy)

Question 16

Where does aerobic respiration take place?

Answer 16

Mitrochondria

Question 17

Why do organsims need the energy made by respiration?

Answer 17

To synthsis larger molecules
Muscle contraction
maintence of body temperature (homeostatsis)
Active transport

Question 18

what is anerobic respiration?

Answer 18

An exothermic reaction in which glucose is broken down to release energy when oxygen is absent

Question 19

word equation for anerobic

Answer 19

Glucose = lactic acid

Question 20

Why is anerobic less efficent then aerobic?

Answer 20

Glucose is only broken down partially so not all energy is transferred

Question 21

Why can anerobic lead to muscle fatigue?

Answer 21

Lactic acid will build up in muscles leading to fatigue as the muscles cannot efficently contract

Question 22

what is fermentation?

Answer 22

A type of anaerobic respiration that occurs in yeast cells

Question 23

word equation for fermentation?

Answer 23

Glucose = ethanol + carbon dioxide +(energy)

Question 24

Why is fermentation used?

Answer 24

Necesarry in products like bread or wine

Question 25

differences between aerobic and anaerobic

Answer 25

aerobic requires oxygen, anarobic does not
Aerobic transfers a greater amount of energy
Aerobic produces co2 and water; anaerobic will produce lactic acid or co2 and ethanol

Question 26

How do muscles store glucose?

Answer 26

As glycogen

Question 27

what happens to the body when the muscles are in use?

Answer 27

The heart rate increases and the arteries dialate ( get wider) to allow more blood to the muscles
breathing rate is increased to allow for more gas exchange
The glycogen stored is now converted back into glucose

Question 28

How is lactic acid transported away from the muscles?

Answer 28

blood flow through the muscles transports lactic acid into the liver, where it is oxidised back into glucose

Question 29

what is metabolism?

Answer 29

The sum of all reaction that take place in a cell or organsim

Question 30

How do cells use the energy transferred by respiration?

Answer 30

by going through enzyme controlled proccess’s in the body e.g sythesis new molecules

Question 31

Give examples of metabolic reactions?

Answer 31

Glucose into starch/glycogen/cellulose
glycerol and fatty acids into lipids
glucose and nitrate ions into amino acids
photosythsis
respiration