Photosynthesis

Question 1

Anabolism

Answer 1

when small molecues are converted into larger molecules - resquires energy in the form of ATP

Question 2

Is ATP high or low energy

Answer 2

High energy

Question 3

light dependent

Answer 3

light must be present

Question 4

What does NADP+ stand for

Answer 4

nicotinamide adnine dinucleotide phosphate

Question 5

photolysis

Answer 5

splitting of water by light into 2H+, 2e- and 1/2 O2

Question 6

Autotroph

Answer 6

a living organism that has the ability to make its own food

Question 7

what is photosynthsis

Answer 7

the process in which co2 and water is being turned into glucose and oxygen

Question 8

Balanced equation for photosynthesis

Answer 8

6CO2 + 6H2O –( sunlight)– C6H12O6 + 6O2

Question 9

Where do plants get their source of CO2

Answer 9

animal and plant respiration, burning of fossil fuels

Question 10

where do plants get their water

Answer 10

soil(enters root via osmosis)

Question 11

where is chlorophyll found

Answer 11

in chloroplast

Question 12

what is the glucose used for in photosynthesus

Answer 12

energy for chemica reactions

Question 13

What is the fate of the oxygen produced

Answer 13

released into atomsphere via stomata/lenticles or used in internal respiration by plant

Question 14

What is the role of phtotsynthesis

Answer 14

plants form basis of our food chain- primary producers.
take CO2 out of atomsphere
O2 produced needed for respiration.
the remains of plants, and the animals they supported, are the main componets of fossil fules

Question 15

How can photosynthesis be artificially enhanced

Answer 15

burning gas in greenhouse, produce carbon dioxie
artificial light sources
Increasing the temperture

Question 16

What are the two stages of phtotsynthesis

Answer 16

Light Stage
Dark Stage

Question 17

Where does the light stage occour

Answer 17

Granum of chloroplast

Question 18

Where does the dark stage occour

Answer 18

Stroma of chloroplast

Question 19

What are the two pathways that the light stage is divided into

Answer 19

Cyclic and Non-Cyclic

Question 20

Describe cyclic phosphorylation

Answer 20

Light shines on electrons in granum. The electrons gain energy and become excited. The electrons are passed though acceptors which cause the electron to lose energy. This energy is used to turn ADP + P into ATP. The low energy electrons return to original Granum

Question 21

Describe non cyclic phosphorylation

Answer 21

Light shines on electrons in granum. Electrons gain energy and become excited.
The electrons are passed though acceptors which cause the electron to lose energy. This energy is used to turn ADP + P into ATP. Water is split when light hits it (Photolysis) into 2e- and 2H+. NADP+ joins with the two low energy electrons and two H+ ions to form NADPH (to dark stage) The newly formed electrons return to a different granum

Question 22

What are the products of the light stage and what are they used for?

Answer 22

O2 (waste, released into atomsphere or used in internal respiration)
ATP ( supplies energy to dark stage)
NADPH (supplies 2H+ ions and 2e- to dark stage)

Question 23

What is the dark stage controlled by?

Answer 23

Enzymes

Question 24

Describe the dark stage

Answer 24

CO2 (from atomsphere or respiration) enters stroma of chloroplast.
ATP supplies energy (from light stage)
NADPH supplies 2H+ and 2e- (from light stage)
CO2 combined with electrons and Hydrogen Ions to form glucose
ADP + P and NADP+ return to light stage

Question 25

Factors that affect the rate of photosynthesis

Answer 25

Light intensity CO2 concentration Temperture

Question 26

Describe how you invetigated the effect of light intensity on the rate of photosynthesis

Answer 26

Used **Elodea** pond weed (photosynthesis under water, we can count the O2 bubbles produced. Cut stem underwater at an angle Controlled other factors by: -temperture (placing thermometer in temperture controlled water bath @25 optimun) -CO2 conc (kept in excess by adding sodium bocarbonate) **vary light intensity by moving lamp** Allow to rest before counting bubbles to **Allow it to start photosynthesis at these conditions** ensure accuracy Measure rate of photosynthesis by counting the no. of O2 bubbles produced per min

Question 27

What is Saturation point

Answer 27

as light intensity increases, the rate of photosynthesis increased up to a certain point. at this point, an increase in light intensity will not prompt an increase in the rate of phtotsynthesis. This point is called the saturation point