Grade 12 Bio Photosynthesis Test Review

structure of a chlorophyll

light absorbing head, hydrocarbon chain

chlorophyll a

blue/green (P700)

chlorophyll b

yellow/green (P680)

reflected

green light

absorbed

red/blue-violet light

granum

stacks of thylakoids

stroma

liquid surrounding thylakoids

shorter wavelengths

bluer light = more energy (photons)

light

electromagnetic radiation

carbon fixation

3 CO2 molecules enter, combine with RuBP with the help of rubisco, makes 3-phosphoglycerate

C3 plants

in hot/dry climates, stomata stay open, releasing water. If stomata close, CO2 can't enter which leads to photorespiration

C4 plants

has a leaf structure that minimizes photorespiration. They separate initial CO2 fixation and the calvin cycle in space, performing these steps in different cell types.

CAM plants

plants close their stomata during the day, collect CO2 at night, and store the CO2 in the form of acids until it is needed during the day for photosynthesis

Engelmenn's experiment

took spyrogira and aerobic bacteria on a slide, placed prism between light and stage, shined the light and noticed the bacteria gather on the sides with more oxygen (red/blue-violet light)

cellular respiration

chemical energy is extracted from food, converts it to ATP, occurs in cytosol/matrix of mitochondria.

photosynthesis

sunlight is converted into chemical energy, occurs in thylakoid membrane of chloroplasts

photosynthetic rates

60% absorbed back into atmosphere, 40% comes to the earth, 5% of the 40% is used in photosynthesis

root uptake force

the force which pulls water up the stem

adhesion

water molecules stick together and pull each other up the stem (because water is polar)

transpiration

as water leaves the leaf (evaporation), new water replaces it

cohesion

water sticks to other polar molecules to be pulled up the stem

endosymbiotic theory

ancestor of cyanobacteria engulfed ancestor of eukaryotic cell, cyanobacteria offered food, eukaryote offered protection

structure of a chloroplast

thylakoid membrane contains light gathering pigments and ETC (photosynthesis happens here)

chlorophyll fluorescence

isolated chlorophyll molecules fluorescence, separated from photosynthetic membrane they are embedded into. Bright white light shined, isolated solution of chlorophyll gives off red light and heat

light dependent reactions

requires: light, H2O, and chlorophyll

occurs in thylakoid membrane

produces: ATP, NADPH, and O2

ATP and NADPH are needed for light independent reactions

light independent reactions (calvin cycle)

requires: ATP, NADPH, and O2

occurs in stroma of chloroplast in light or dark conditions

produces: glucose, ADP+Pi, NADP+

reduces CO2 to glucose

photophosphorylation

making ATP through light energy

the role of CO2

taken in, reduced to glucose

the role of O2

produced in light independent reaction

photosystem II

contains P680, begins when a proton energizes an electron in P680, transfers electrons to PQ and makes O2 which is released in the lumen

photosystem I

transfers electrons

mitochondria

double mb, smooth outer mb/folded inner mb, ETC and chemiosmosis--> cristae, krebs occurs in matrix, pathways= glucose, 3-carbon sugars, CO2, ATP, H2O released

chloroplasts

double mb, smooth outer/inner mb, ETC and chemiosmosis--> thylakoid mb, stroma found in inner mb and intermb space, pathways= sunlight, ATP & NADPH, CO2, 3-carbon intermediates which can be used to make other carbohydrates

reactants

CO2, H2O

products

O2, glucose

light dependent (vs)

generates electrochemical gradient by pumping protons, occurs in thylakoid mb, contains 1 proton pump, terminal electron acceptor= NADP+, water is required

oxidative phosphorylation (vs)

generates electrochemical gradient by pumping protons, occurs in mitochondrial matrix, contains 3 proton pumps, terminal electron acceptor= O2 which eventually makes water, water is produced

purposes of carbohydrates

used directly in photosynthesis, converted to starch and stored in stems and roots, converted to cellulose, converted to sucrose

cutin

structure: waxy substance on leaves

function: prevent loss of water by evaporation

upper epidermis

structure: single layer of cells that fit tightly together

function: protects the leaf tissues from dehydration and makes cuticle

palisade mesophyll

structure: slender cells located side by side containing chloroplasts

function: makes most of food because of large amounts of chloroplasts

spongy mesophyll

structure: irregularly arranged cells containing some chloroplasts with air between

function: is the main area of O2/CO2 exchange

lower epidermis

structure: identical to upper

function: identical to upper but no cuticle is made

stomata

structure: openings in the bottom of the leaf

function: allows CO2 to enter leaf and O2/H2O vapour to leave

guard cells

structure: pairs of kidney shaped cells located above stomata

function: expand and contract to open or close stomata