Cell Respiration and Photosynthesis Flashcards
what is cell respiration?
the controlled release of energy from organic compounds to produce ATP
why is ATP a good source of energy?
ATP from cell respiration is immediately available
what does cell respiration involve generally?
the oxidation and reduction of compounds
what is oxidation in terms of electrons and hydrogen ions?
- involves the loss of electors
- the loss of hydrogen ions
what is reduction in terms of electrons and hydrogen ions?
- gain of electrons
- gain of hydrogen ions
what happens to glucose in cell respiration?
glucose in the cytoplasm is broken down by glycolysis into pyruvate, yielding a small amount of ATP
outline the 3 steps of glycolysis
- phosphorylation: adding phosphates (2 ATP to 2 ADP)
- lysis: splitting glucose into 2 trios phosphate molecules
- oxidation: 2 hydrogens removed from trios phosphate
what does phosphorylation do to molecules?
makes them less stable
what happens to pyruvate during anaerobic respiration?
pyruvate is converted into lactate, ethanol and CO2 in the cytoplasm, which no further ATP yield (aka 2 ATP from glycolysis produced)
what happens to pyruvate during aerobic respiration?
it’s decarboxylated and oxidized
what happens in the link reaction generally?
pyruvate is converted into acetyl CoA
what happens to the acetyl groups in the Krebs cycle?
oxidation of acetyl groups is coupled to the reduction of hydrogen carriers, liberating CO2
what happens to the energy released by oxidation reaction?
the energy released is carried to the cristae of the inner mitochondrial membrane by reduced NAD and FAD
what is the transfer of electors in the electron transport chain coupled to?
Proton pumping
what happens to protons in chemeosmosis?
protons diffuse through ATP synthase to generate ATP
why is oxygen needed in the electron transport chain?
oxygen needed to bind with the free protons (hydrogen) to form water to maintain the hydrogen gradient
what is photosynthesis?
the production of carbon compounds in plant cells using light energy
what is visible light from the sun composed of?
a range of wavelengths (colors), with red having longest wavelength and violet the shortest (red is lower energy, violet is highest energy)
what is chlorophyll and what does it do?
it’s the main photosynthetic pigment (includes a and b) and absorbs red and blue light most effectively, and reflects green light the most
what does the photolysis (splitting with light) of water produce?
- electrons for light dependent reactions
- protons for the reduction of NADP
- oxygen as a waste product
why is energy needed in photosynthesis?
to produce carbohydrates and other carbon compounds from CO2
describe the relationship between the structure and function of mitochondrion
- cristae provide more SA
- small inter-membrane space creates gradient
- matrix for reactions
outline the changes to earth’s atmosphere, oceans, and rock deposition due to photosynthesis
- prokaryotes started photosynthesis 3.5 bill years ago
- great oxidation event rose O2 levels to 2% 2.2 bill years ago
- earth’s first glaciation period @ the same time
- boring billion followed: O2 levels about 2%
- due to land plants, O2 levels grew to todays (21%)
- rise in O2 levels led to iron rick rocks
what is an absorption spectrum for chlorophyll
measures how much light is absorbed versus the wavelength
describe chromatography
- filter paper with tissue on end is dipped into solvent
- solvent ascends carrying pigments from tissue
- diff pigments moves at different rates: creating different layers of pigment
- r-value calculated by rise of pigment/rise of tallest pigment
outline the 3 limiting factors in photosynthesis
- light: light dependent reactions shut down at night
- temp: enzymes work better at higher temps because more kinetic energy, but too high of temp drops photosynthesis
- CO2 concentration: can shut down Calvin cycle in carbon fixation step
define oxidative phosphorylation
when hydrogen and CO2 are removed from pyruvate in link reaction + last step of respiration
summarize the products and location of glycolysis, link reaction, Krebs cycle, and oxidative phosphorylation (including the electron transport chain and chemeosmosis) in cell respiration
- glycolysis (cytoplasm): glucose in - 2 pyruvate out, 2 net ATP out, 2 NADH out
- link reaction (mitochondrial matrix): 2 pyruvate in - 2 acetyl CoA out, 2 CO2 out, 2 NADH out
- Krebs cycle (mitochondrial matrix): 2 acetyl CoA in - 4 CO2 out, 2 ATP out, 6 NADH out, 2 FADH2 out
- Oxidative phosphorylation (inner membrane of mitochondria): 10 NADH in, 2 FADH2 in - 25-28 more ATP out
