Unit 3: Cellular Energetics Flashcards
Enzymes
biological catalyst that aids in chemical reactions by lowering the activation energy
- always proteins and end in ASE
The substrate enters the active site, chemical reaction happens, and products leave the enzyme
- more enzymes = linear and increasing reaction rate
- more substrate = limited reaction rate b/c there’s only so many enzymes in use
Induced fit = substrate binds and causes conformational change in enzyme
Cofactor = non protein molecules that bind to enzymes to increase enzyme activity
Environmental effects on enzymes
- enzymes have optimal environments and deviations affect the rate of reaction
LOW TEMP = doesn’t denature just makes it move slower
HIGH TEMP = makes things faster until you hit optimum then they denature
PH RANGE = deviating too much towards acid or base causes denaturing
Competitive vs Noncompetitive Inhibitors
COMPETITIVE = molecule binds directly to active site to prevent substrate from binding (actively competes with substrate)
NONCOMPETITIVE = molecule binds to the ALLOSTERIC SITE causing a conformational change in active site preventing substrate from binding
Reaction Coupling
using energy from one reaction to allow/power a second reaction (ex. secondary active transport)
ATP Hydrolysis
ATP is broken down and always released energy that can be used for other reaction (separate one phosphate group off of it and turn it into ADP)
ATP phosphorylation
reattachment of phosphorus + creation of new ATP molecules
- ATP synthase is the enzyme that catalyzes reaction of ADP - ATP by using an H+ ion gradient and facilitated diffusion
Oxidative Reduction Reaction
reaction coupling which involves the transfer of electrons from one molecule to the other (use high energy electron carriers)
OIL RIG
Oxidation Is Loss
Reduction Is Gain
Pigment
any molecule that absorbs light of a certain wavelength
- chlorophyll is the most used pigment
- carotenoids absorb red light
- using multiple pigments MAXIMIZES the # of possible wavelengths plants absorb (more energy = more glucose)
- cumulative absorption = sum of all the individual pigments
Light reaction
LIGHT REACTION: light + water = O2 + NADPH + ATP
1. light absorbed in ps1 and ps2 in thylakoid membrane
2. electrons are generated from splitting water into O2 (waste) and H+ ions
3. electrons move through the ETC fueling active transport of H+ ions through membrane (electron gets to end of ETC and makes NADPH)
4. H+ ions are then facilitated through ATP synthase creating ATP
O2 is waste product that diffuses straight out to the atmosphere
ATP + NADPH are used in the next process to make glucose
Calvin Cycle
ATP + NADPH = Glucose + NADP+ + ADP
- Use ATP and NADPH to fuel carbon fixation
- glucose is made and NADP+ and ADP are recycled to light reaction
Plants use glucose for cellulose and starch
Photosynthesis
Converting light energy into chemical energy
light + CO2 + water = O2 + glucose
Chemiosmosis
movement of CHARGED IONS through a protein channel ALONG the concentration gradient
Carbon Fixation
Necessary bc carbon dioxide is biologically unusable for plants
- the capture of CO2 and incorporating in into organic molecules to make glucose
(requires energy from ATP and NADPH)
Autotroph vs Heterotroph
Autotroph: makes its own food (plants and fungi make glucose for themselves)
-Photoautotroph = photosynthesis produces food
-Chemoautotrophs: organisms make food through oxidation of inorganic compounds (only in extreme environments)
Heterotroph: rely on other sources of energy (consume) can’t make own energy
Cellular respiration
process of turning glucose into ATP in the mitochondria (glycolysis, Krebs cycle, oxidative phosphorylation)
glucose = water + ATP + CO2
Glycolysis
- occurs in cytoplasm of ALL cells (not just specific to mitochondria)
- converts glucose into 2 pyruvates using enzyme catalyzed reactions
- small net production of ATP and NADH
Krebs Cycle
- occurs in Matrix
- occurs 2x per glucose molecule (each pyruvate)
- series of enzyme catalyzed reactions that produce CO2 as waste, NADH, FADH2, and small ATP production
NADH and FADH2 are high energy electron carriers
Oxidative Phosphorylation
-Occurs in the inner membrane
- uses NAPH+ FADH2 to power ETC (generates H+ gradient high in intermembrane space low in matrix)
- gradient is used to produce ATP via chemiosmosis and ATP synthase
- O2 is the FINAL ELECTRON ACCEPTOR which forms water as waste (w/o O2, electrons won’t move)
-this process creates the necessary energy for survival
NADH drops electron to become NAD+ and FADH2 drops electron to become FAD
Aerobic vs Anaerobic respiration
Aerobic: oxygen is required
Anaerobic: production of energy w/o consumption of oxygen (fermentation)
- starts with glycolysis exactly how we learned it
Pyruvate Oxidation vs Fermentation
when there is O2, pyruvate oxidation can occur (pyruvate = Acetyl CoA + NADH + CO2)
FERMENTATION: when there’s no O2 (backup energy source anaerobic respiration, not enough for sustained energy in Aerobic organisms)
- glycolysis goes normal but then pyruvate could turn into two byproducts (lactate = lactic acid fermentation, ethanol = alcohol fermentation)
- uses oxidation (NADH -> NAD+) and NAD+ recycles to glycolysis to make a little ATP
MAJOR WASTE PRODUCT = CO2
