BIO EXAM REVISION REAL

nadh and fadh2

: loaded acceptor molecules

unloaded version of fadh2→

fad

unloaded versions of nadh →

nad+

matrix of mitochondria:

fluid filled spaces inside inner membrane of mitochondira

cristae:

folded inner membrane of the mitochondria

cytosol

: the fluid present in the cell 

cytochromes

: electron transferring protein

-purpose of cellular respiration

is the process that releases a useable form of energy (ATP) from glucose (converts energy)

why does cellular respiration occur

because glucose cant be used by cells and must be converted into useable form of energy

cellular respiration energy used for examples

fuel chemical reactions, cellular processes, body processes, biochemical reactions

word equation: aerobic respiration

glucose + oxygen → carbon dioxide + water + energy

3 stages of aerobic respiration

glycolysis, krebs cycle, etc

glycolysis what it does and forms

-breaks down glucose into 2 pyruvate molecules,

-energy is released to form 2 atp, nadh

-loaded molecules from glycolysis move to cristae for ETC

krebs cycle

1 pyruvate forms co2, energy is released to form: 2atp,loaded acceptor molecules(nadh, fadh2) occurs twice.loaded acceptor molecules taken to crisate for ETC

electron transport chain

-occurs in the cristae of mitochondria

-ielectrons and h+ from nadh and fadh2 are passed along a series of cytochromes,

-oxygen is the final electron acceptor and combines with hydrogen to form h2o.

-energy is released to drive atp production which results in 26 or 28 atp

atp yield for aerobic respiration

-30 or 32 atp depending on type of cell per glucose

why theoretical atp yield ois higher than real one

process is not completely efficient due to energy used during transport of substances into mitochondria

which respiration has faster atp production

anaerobic respiration has rapid atp production, aerobic is slower

is aerobic respiration continous

Continuous process as long as glucose is available (no toxic products)

which respiration has a more efficient energy transfer

aerobic respiraiton has a more efficient energy transfer (i.e. more ATP produced per glucose molecule)

role of coeznymes

nad and fad help carry electrons and hydrogen ions during glycosis and the krebs cycle which are then transferred to the electron transport chain, this enables ADP and Pi to join, forming ATP

the inner membrane of the mitochondria is folded into … to

cristae to increase the surface area which maximises atp production

how does the cristae maximise aerobic respiration

Provide larger surface area for the electron transport chain proteins and ATP synthase to be embedded in. 
This maximises the mitochondrion’s ability to generate ATP efficiently.
 

lactic acid fermentation human muscle cellswhen

extreme exercise or when bursts of power are required to perform an activity more quickly than oxygen can be delivered to the cells.

anaerobic respiration animal

During high intensity muscle use or explosive bursts of energy, animals that require quick energy in large amounts rely on anaerobic respiration to provide this level of energy.

lactic acid fermentation examples

used by 100m sprint runners, weightlifters, or the cheetah running after their prey.

rubisco:

an enzyme that converts inorganic co2 to organic carbon, can catalyze reactions with either oxygen or co2

bundle sheath cells:

a layer of cells in plant leaves and stems that forms a sheath surrounding the vascular bundles.

guard cells:

control stomata opening and closing.

carbon fixation

is the process of converting inorganic carbon from the atmosphere into organic molecules

photorespiration -

process that can occur when the concentration of oxygen in the leaf is higher than the concentration of carbon dioxide

organic compound:

contain carbon-hydrogen bonds, examples include glucose

inorganic compound

generally do not contain carbon-hydrogen bonds. like co2, water,

is the light independent stage is the same for all three plant types.

yes, the difference is the location or time of the light independent stage and carbon fixation.

do c3 cam and c4 plants all go thru same process

yes

light dependent process (same for all plants)

1. light energy absorbed by chlorophyll

2. causes water to be split into hydrogen ions and oxygen by light energy, (2 electrons released)

3. nadp+ picks up hydrogen ion to form nadph

4. electron transport chain forms atp from adp + pi

5. oxygen diffuses out of grana and released from the leaf through open stomata

photorespiration

process that can occur when the concentration of oxygen in the leaf is higher than the concentration of carbon dioxide

why is photorespiration bad

glucose cannot be created and it results in use (waste) of ATP

c3 plant light independent reaction

1. co2 enters thru stomata of leaf and diffuses into the mesophyll cell and moves into the chloroplast into the stroma

2. nadph and atp move from grana to stroma for light independent stage,

3. co2 enters the calvin cycle in c3 plants and carbon fixation occurs to produce glucose (rubsico catalyses reaction between co2 and rubp → begin carbon fixation)

4. unloaded carriers (adp+Pi and nadp+) move back into the light dependent stage to pick up more hydrogen ion and electrons.

c4 plant light independent reaction

• plant initially fixes co2 from the environment into malate via a different enzyme in the mesophyll cells

• malate is transported to bundle-sheath cells for the calvin cycle.

• malate is converted back into co2, the released co2 creates a high concentration near rubisco and calvin cycle begins as rubisco catalyses the reaction between co2 and rubp resulting in carbon fixation

cam plant light independent reaction

• stomata open at night to collect co₂ and release oxygen; initial carbon fixation occurs when co₂ is converted into malate and stored in vacuoles.

• when sun rises, malate from vacuoles is converted back into co₂; rubisco catalyses the reaction between co2 and rubp which results in carbon fixation .

when does the light dependent stage and calvin cycle occur CAM

• light-dependent stage and calvin cycle happen during the day.

c3 plants are

• "normal" plants with no adaptations to reduce photorespiration.

• susceptible to photorespiration in hot/dry conditions as live in temperate environment (low temp, water available).

• approximately 85% of plant species (e.g., rice, wheat, fruits, vegetables).

• temperate environment (low temperatures, water available)

photorespiration in C3 plants when

low co₂, high o₂ conditions: photorespiration occurs.

high temp impact c3 plant photorespiration

oxygen binds to rubisco more frequently due to higher diffusion rate into the cell

rubiscos purpose in photosynthesis

catalyses the reaction between CO₂ and RuBP, resulting in carbon fixation.

can catalyse reactions with either oxygen or carbon dioxide.

high light intensity impact c3 plant photorespiration

oxygen builds up in mesophyll cells as stomata close.

adaptions in C4 AND CAM plants which maximise the efficiency of photosynthesis

fix co2 from the environment into malate, minimises the interaction between o2 and rubisco , minimise photorespiration

cam plant adaption better photosynthesis

separation of the initial co2 fixation stage at night → conserves water by having stomata open at night and then the LDS and LIS occur during the day

c4 plant adaption better photosynthesis

physical separation of INITIAL carbon fixation (co2→ malate) and remaining LIR as low o2 concentration in bundle sheath cells

cam plants

• adapted to arid (high daytime temp, intense sunlight, low soil moisture, low humidity) environments (e.g., deserts). very water-efficient but slow.

• examples: cacti, succulents.

C4 plants

• only ~3% of vascular plants, common in high temperature, high humidity, and high light intensity environments.hot/tropical environments (e.g., corn, sugarcane)

• physical separation of carbon fixation and rest of LIR is an adaption to minimise photorespiration

light independent stage for C3 C4 and cam occurs in

stage occurs in mesophyll cells

c4 plants remaining light independent stage occurs in

buncle sheath cells

cam plant evaluate photosynthesis efficiency

very efficient but also very slow

where does the light dependent stage occur for all!

thylakoid membrane of grana in chloroplast

where is chlorophyll contained

grana of the chloroplast in the mesophyll cell

light dependent and independent stage cam and c3 plants occurs in

mesophyll cells

light independent first and last step

loaded carriers and atp from light dependent stage move to the stroma for the light independent stage

unloaded carriers (adp+pi) move back to light dependent stage for more h+ and e-

what is photosynthesis

a biochemical pathway which occurs in plants and other organisms with chloroplasts

limiting factors

environmental conditions or resources that restrict the rate at which photosynthesis occurs.

thylakoid

membrane-bound compartments containing chlorophyl

chlorophyll

green pigment responsible for absorbing light energy in photosynthesis

stroma

stroma is the fluid filled space which is the site of the light independent reactions

purpose of photosynthesis

convert light energy into chemical energy in the form of glucose

does photosynthesis continuously cycle between light independent and dependent

yes

inputs of photosynthesis

water and carbon dioxide

outputs of photosynthesis

outputs are oxygen and glucose

photosynthesis word equation

water + carbon dioxide → via chlorophyll light energy to oxygen + glucose

chemical equation

6h2o +6co2→via chlorophyll light energy to 6o2+c6h12o6

light dependent stage inputs

h2o. nadp+. adp+pi

light dependent stage outputs

o2, nadph, atp

light independent stage input

nadph, co2, atp

light independent stage outputs

glucose (c6h12o6)nadp+, adp+pi

coenzymes in photosynthesis

nadp+ and atp

role of nadp+

acts as an electron carrier, carries hydrogen to become nadph

adp+pi becomes

atp

where does photosynthesis occur

photosynthesis occurs in the chloroplasts

What are chloroplasts

chloroplasts are specialised organelles where photosynthesis occurs

where in the chloroplasts does the light independent reaction occur!!

stroma is where the light independent reaction occurs

grana are

stacks of thylakoid discs

importance high sa:v chloroplast

-increased light absorption, better exchange of materials

nadph role

carrys electrons and hydrogen ions

do coenzymes cycle between light dependent and independent stage

yes they do

light dependent stage occurs in

thylakoid membranes of the grana in chloroplasts

light dependent stage 1st step

light energy absorbed by chlorophyll

light dependent stage 2nd step

causes water to be split into hydrogen ions and oxygen by light energy, (2 electrons released)

light dependent stage 3rd step

nadp+ picks up hydrogen ion to form nadph

light dependent stage 4th step

electron transport chain form atp from adp + pi

light dependent stage 5th step

oxygen diffuses out of grana and released from the leaf through open stomata

why light dependent stage occur in the thylakoid membrane

because there is a high concentration of chlorophyll inside the thylakoid membrane

light independent stage occurs in

stage occurs in the stroma

light independent stage 1st step (all)

nadph and atp move from grana to stroma for light independent stage,

light independent stage 2nd step C3

co2 enters the calvin cycle in c3 plants and carbon fixation occurs to produce glucose ( (rubsico catalyses reaction between co2 and rubp → begin carbon fixation)

factors that influence the rate of photosynthesis

light intensity, water availability, absorption of light wavelengths, co2 concentration,

limiting factors of photosynthesis

light intensity, co2 concentration, temperature

enzyme related factors photosynthesis

temperature, ph, enzyme inhibitors

co2 concentration impact on c4, plants

c4 has high rate of photosynthesis even w low co2 concentration due to split cycles,

co2 concentration impact on c3 plant

c3 plant require certain amount co2 to begin,

co2 concentration impact on cam plants

cam plants arent v affected by co2 concentration as store co2 at night in form of malate