Topic 5 - On the Wild Side

Question 1

What is a Light-Dependent Reaction?

Answer 1

Using light and hydrogen energy from photolysis to produce reduced NADP and ATP

Question 2

What is a Light-Independent Reaction?

Answer 2

Uses reduced NADP and ATP to reduce CO2 to carbohydrates

Question 3

What is Predation?

Answer 3

The relationship between organisms in which one benefits and feeds off of the other

Question 4

What is a Population?

Answer 4

A group of organisms living in the same area belonging to the same species with the ability to interbreed

Question 5

What is a Community?

Answer 5

A group of organisms living in the same area, all belonging to different species

Question 6

What are the Different Abiotic Factors?

Answer 6

• Solar Energy Input
• Climate
• Topography

Question 7

How is Solar Energy Input Effected?

Answer 7

• Latitude
• Season
• Cloud Cover

(Viral for photosynthesis and acts as an environmental cue for reproduction)

Question 8

What is Topography?

Answer 8

The slope of land and it’s drainage

Question 9

What is an Edaphic Factor?

Answer 9

Factors associated with soil pH and the mineral concentration

Question 10

What is Mutualism?

Answer 10

A relationship between species where both partners benefit.

E.g humans and digestive bacteria

Question 11

What is a Density Dependent Biotic Factor?

Answer 11

Where the effects depend on the population density. (E.g the larger the population density, the greater the competition between species)

Question 12

What is an Anthropogenic Factor?

Answer 12

Abiotic or biotic factors that occur because of human activity

Question 13

What is Primary Succession?

Answer 13

When new habitats form where there has never before been a community

Question 14

What is Secondary Succession?

Answer 14

When habitats form where an existing community has been cleared

Question 15

What are Pioneer Species?

Answer 15

The first species to colonise the forming habitat. They can usually cope with extreme conditions (e.g lack of soil or water)

Question 16

What is a Climax Community?

Answer 16

Usually dominated by trees, this is a stable community that is achieved in succession and is usually unchanged

Question 17

What is Deflected Succession?

Answer 17

A form of succession that remains stable because of human activity

Question 18

What is Primary Productivity?

Answer 18

The rate in which energy is transferred into organic molecules in an ecosystem

Question 19

What is an Autotroph?

Answer 19

Also known as a producer, these are organisms that make their own organic compounds

Question 20

What is a Chemosynthetic Autotroph?

Answer 20

Organisms that make organic molecules from chemical reactions instead of light

Question 21

What is Photolysis?

Answer 21

The splitting of water, using light energy

Question 22

How is Hydrogen Stored in Carbohydrates?

Answer 22

Hydrogen and CO2 react and the CO2 is reduced to form glucose

Question 23

Why is Photosynthesis Important?

Answer 23

• Animals can’t make all organic molecules so are dependent on the plants
• Oxygen is released so that organisms can anaerobically respire

Question 24

What is the Thylakoid Membrane?

Answer 24

• System of flattened sacs

- Proteins and electron carriers are stored here

Question 25

What is a Thylakoid Space?

Answer 25

- The fluid within the thylakoid membrane | - Contains enzymes for photolysis

Question 26

What is the Stroma?

Answer 26

- Fluid surrounding thylakoid membranes | - Contains all enzymes for light-dependent reactions

Question 27

What is a Starch Grain?

Answer 27

Stores photosynthesis products

Question 28

What is a Granum?

Answer 28

Stack of thylakoids

Question 29

What is the Inner Membrane of a Chlorophyll Molecule?

Answer 29

Contains transporter molecules which regulate passage of substances

Question 30

Explain the Process of the Light-Dependent Reaction?

Answer 30

- Light energy raises 2 electrons in each chlorophyll - Electrons become ‘excited’ - Electrons travel through electron carriers in electron transport chain - PSII electrons pass through oxidation/reduction reactions and lose energy as they do so - Lost energy used to make ATP - Lost electrons are replaced - Photolysis occurs to create O2, H and electrons

Question 31

What is the Name of the Process That Makes ATP in Photosynthesis?

Answer 31

Photophosphorylation

Question 32

What is the Structure of ATP Made Up Of?

Answer 32

- Adenine (organic base) - Ribose (sugar) - 3 phosphate groups

Question 33

What Happens When the 3rd Phosphate Group in ATP is Removed?

Answer 33

It becomes hydrated and bonds with surrounding water molecules

Question 34

How is ATP Produced?

Answer 34

From ADP and an inorganic phosphate

Question 35

Where does the Light-Independent Reaction Occur?

Answer 35

Stroma in the chloroplast

Question 36

Where Does the Light-Dependent Reaction Occur?

Answer 36

Thylakoid Membrane in the Chloroplast

Question 37

Explain the Process of the Light-Independent Reaction?

Answer 37

- CO2 combines with 5C compound (RuBP) - This is catalysed by RuBISCO - 6C compound breaks down into X2 3C compound (GP) - 3C compound is reduced, forming sugar phosphate (GALP) - (For reduction, H from LD reaction used and ATP provides energy) - GALP forms 6C sugar (hexose) or recreates RuBP for repeat of cycle - Hexose can convert into amino acids/lipids

Question 38

What is Carbon Fixation?

Answer 38

When inorganic carbon in CO2is converted to organic molecules

Question 39

What is a Trophic Level?

Answer 39

The position of a species in the food chain

Question 40

What is a Primary Consumer?

Answer 40

A herbivore

Question 41

What is a Secondary Consumer?

Answer 41

Carnivores (feed on Primary consumers)

Question 42

What is a Tertiary Consumer?

Answer 42

Carnivores at the top of the food chain (also known as top carnivores)

Question 43

What is a Food Web?

Answer 43

A system of interlocking food chains in an ecosystem

Question 44

What is a Detritivore?

Answer 44

Primary consumers that feed in dead organic material (e.g woodlice and earthworms)

Question 45

What are Decomposers?

Answer 45

Bacteria and fungi species that feed on remains of dead organisms

Question 46

Why is Only a Small Amount if Light Absorbed in Photosynthesis?

Answer 46

Because chlorophyll can only absorb certain wavelengths

Question 47

What are the Limiting Factors of Photosynthesis?

Answer 47

- Light Intensity - Temperature - CO2 concentration

Question 48

What is Gross Primary Productivity (GPP)?

Answer 48

The rate that energy is incorporated into organic molecules by an ecosystem

Question 49

How is the Percentage Efficiency of Photosynthesis Calculated?

Answer 49

GPP divided by light energy arriving at plant X 100