Lecture 8

Question 1

Autotrophs

Answer 1

Don’t require organic carbon, use inorganic carbon as carbon source, fix atmospheric oxygen into organic carbon

Question 2

Photoautotrophs

Answer 2

Use light energy to power carbon fixation

Question 3

Chemoautotrophs

Answer 3

Lithotrophs, use redox energy energy to power carbon fixation (chemosynthesis), prokaryote only

Question 4

Heterotrophs

Answer 4

Require organic carbon for carbon source

Question 5

Photoheterotrophs

Answer 5

Use organic carbon for carbon source and light for energy source, prokaryote only

Question 6

Chemoheterotrophs

Answer 6

Use organic carbon for carbon source and energy source, humans

Question 7

Thylakoid Membrane

Answer 7

Site of light reactions

Question 8

Stroma

Answer 8

Site of Calvin Cycle

Question 9

Chloroplast

Answer 9

Double-membrane bound with stacks of internal membranes called thylakoids

Question 10

Carbon Fixation

Answer 10

Converting atmospheric carbon (CO2) to organic carbon (e.g. glucose), low energy carbon (oxidized) to high energy carbon (reduced)

Question 11

Light Reactions

Answer 11

Use energy carried by light and convert it into chemical energy in the form of ATP and NADPH, which are used to drive Calvin Cycle

Question 12

Pigments

Answer 12

Ring shaped molecules that absorb energy

Question 13

Photosystems

Answer 13

Protein complexes which sit across thylakoid membrane, contain pigments

Question 14

Xanthophyll

Answer 14

Purple accessory pigment, good antioxidant

Question 15

Electron Transfer Chain

Answer 15

A set of increasing strength electron acceptors (higher and higher electronegativity), allow energy to be released in small discrete steps, changes energy into a valuable form (redox)

Question 16

Chemiosmosis

Answer 16

Formation of ATP using ATP synthase and proton gradient

Question 17

Photophosphorylation

Answer 17

Formation of ATP in photosynthesis

Question 18

ATP synthase

Answer 18

Enzyme complex that couples an endergonic process (ADP to ATP) with an exergonic process (Diffusion of proton gradient)

Question 19

NADPH

Answer 19

Vitamin from our diets, electron carrier in photosynthesis

Question 20

Calvin Cycle

Answer 20

Light independent reactions, uses energy from light dependant to convert carbon dioxide to sugar

Question 21

Carbon Fixation

Answer 21

One CO2 molecule is added per turn of cycle, 3 turns of cycle produces one molecule of G3P

Question 22

G3P

Answer 22

Glyceraldehyde-3-phosphate, 3 carbon molecule, direct product of Calvin cycle

Question 23

Reduction

Answer 23

2 G3P molecule are converted to 1 molecule of glucose, carbon is reduced by electrons from NADPH (originally from water, molecular rearrangements increase number of carbon hydrogen bonds

Question 24

Regeneration

Answer 24

RuBP is regenerated in third phase, set of complicated reactions requiring ATP

Question 25

RuBP

Answer 25

Ribulose bisphosphate, sugar, substrate of rubisco

Question 26

Rubisco

Answer 26

Greatest enzyme on planet

Question 27

Cyclic Electron Flow

Answer 27

Make ATP without NADPH, excited electron from photosystems I feeds back into ETC to make ATP via phosphorylation without making NADPH, decision is made by [ADP], if [ADP] is high, cyclic electron flow occurs