unit 3 (topic 5)

Question 1

photosynthesis first evolved in?

Answer 1

prokaryotes
(cyanobacteria: early prokaryotes capable of photosynthesis)

Question 2

site of photosynthesis (internally and externally)

Answer 2

• leaves in plants; stomata (pores) allow this
• chloroplast: organelle for the location of photosynthesis (found in mesophyll: cells that make up the interior tissue of the leaf)

Question 3

chloroplast structure

Answer 3

• double membraned
• stroma: aqueous interior fluid
• thylakoid: form stacks (grana)
• chlorophyll: green pigment in thylakoid membranes

Question 4

formula for photosynthesis

Answer 4

6 CO2 + 6 H2O + light –> C6H12O6 + 6 O2

redox reaction

Question 5

redox reaction

Answer 5

reaction involving complete/partial transfer of one or more electrons from one reaction to another

OIL RIG

Question 6

oxidation

Answer 6

loss of electrons

Question 7

reduction

Answer 7

gain of electrons

Question 8

two stages of photosynthesis

Answer 8

light reactions and Calvin cycle

Question 9

what type of energy is light

Answer 9

electromagnetic energy

Question 10

photons

Answer 10

particles that make up light and travel in waves

Question 11

wavelength

Answer 11

• distance from crest of one wave to crest of another
• visible light: 380 nm through 750 nm
• short wavelengths: higher energy
• long wavelengths: lower energy

Question 12

electromagnetic spectrum

Answer 12

entire range of light

Question 13

when light interacts with matter, it can be:

Answer 13

reflected
transmitted
absorbed

Question 14

photosynthetic pigments

Answer 14

CHLOROPHYLL A: primary pigment, involved in light reactions, blue/green pigment
CHLOROPHYLL B: accessory pigment, yellow/green pigment
CAROTENOIDS: broaden the spectrum of colors that drive photosynthesis, yellow/orange pigment
–> photoprotection carotenoids absorb and dissipate excessive light energy that could damage chlorophyll or interact with oxygen

Question 15

heterotrophs vs autotrophs

Answer 15

H: rely on other organisms for food
A: produce their own food from surroundings

Question 16

light reactions

Answer 16

• occur in thylakoid membrane in photosynthesis
• converts solar energy to chemical energy (NADPH and ATP)

Question 17

photosystems

Answer 17

reaction center and light capturing complexes

REACTION CENTER: complex of proteins associated with chlorophyll A and an electron acceptor
LIGHT CAPTURING COMPLEXES: pigments associated with proteins

Question 18

photosystem 2

Answer 18

reaction center P 680 (absorbs light at 680 nm)

Question 19

photosystem 1

Answer 19

reaction center P 700 (absorbs light at 700 nm)