Biology 141 - Exam 2

metabolism

chemical process that occurs within organisms to maintain life

metabolic pathway

A series of chemical reactions that builds complex or breaks complex molecules

Catabolism

breakdown process of complex molecule to simpler (release NRG)

Anabolism

building process of smaller molecules to larger ones

Bioenergetics

study of how energy flows through living organisms

energy

capacity to cause change

kinetic energy

energy related to relative motion of molecules

thermal energy

kinetic energy associated with random movement of atoms/molecule

Potential energy

possessed energy not moving, by molecule or atom

Chemical energy

potential energy available for release in chemical reaction

Thermodynamics

study of energy transformation that occurs in collection of matter

1st law of thermodynamics

energy of universe is constant (not created/destroyed)

2nd law of thermodynamics

energy transfer increases entropy of universe (energy lost as heat)

entropy

measure of randomly collected matter/energy (disorder of energy) (randomness)

spontaneous process

time-evolution of system regarding energy states

free energy

portion of system energy that can perform work

exergonic reaction

reaction that proceeds net release of free energy

endergonic reaction

reaction that absorbs energy from surroundings

chemical work

pushing of endergonic reactions

transport work

pumping substances across membrane (against conc. gradient)

mechanical work

using energy to contract cells, move chromosomes, etc.

energy coupling

way cells manage resources using exergonic process to drive endergonic one

Phosphorylated intermediate

recipient molecule in process that contains phosphate group covalently bonded

Enzyme

organic substance (protein) that acts as catalyst to bring about a specific biochemical reaction

Isomerase

makes isomers flip

Kinase

adds phosphate

Dehydrogenase

big hydrogen remover

Catalyst

chemical agent that speeds up chemical reaction without being consumed

Activation energy

energy required to contort reactant molecule to break bonds

Substrate

reactant an enzyme acts on

Enzyme-substrate complex

complex of substrate attached to enzyme's active site

Active site

location on enzyme where substrate binds to

Induced fit

model that idealizes the interaction of substrate and enzyme

Cofactor

helpful non-proteins for catalytic activity

Coenzyme

organic cofactor

Competitive inhibition

inhibition mimicking substrate and blocks active site, competing with substrate

Non-competitive inhibition

inhibition where chemicals bind to allosteric site and changes the structure of active site (substrate concentration does not affect)

Temperature

variable that break bonds (H-bonds) at high levels and not enough energy at low for enzyme reactivity

pH

variable that can cause denaturation in enzymes (level of H+ ion concentration)

Salinity

affects side chains because clogged by ions

Inhibitors

non-comp or comp

Activators

binds to site & facilitates substrate conversion (copper)

Allosteric regulation

The binding of a (regulatory) molecule to a protein at a site that affects the function of the protein at a different site

Cooperativity

amplification of response of enzyme to substrate - a type of allosteric regulation

Feedback inhibition

metabolic pathways halted by inhibitory binding of end product to an enzyme earlier in pathway

ATP

nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed. This energy is used to drive endergonic reactions in cells

Fermentation

catabolic process where partial degradation of sugars or other organic fuel occur without the use of oxygen

Aerobic respiration

efficient metabolic process where oxygen is used as final electron carrier

Cellular respiration

catabolic pathways of aerobic/ anaerobic respiration - break down of molecules and use of ETC to make ATP

Redox-Reaction

transfer of electrons with reduction and oxidation reactions

Reducing agent

The electron donor in a redox reaction.

Oxidizing agent

The electron acceptor in a redox reaction.

Nicotinamide adenine dinucleotide

NAD(H)" coenzyme electron carrier

Flavin adenine dinucleotide

FAD(H2)" redox cofactor electron carrier

Nicotinamide adenine dinucleotide phosphate

NADP(H)" cofactor electron carrier from water

ETC

electron transport chain, a sequence of e- carrier molecules that shuttle e- down series of redox reactions for release of energy for ATP production

Glycolysis

series of reactions that ultimately split glucose into pyruvate and occurs in cytosol of almost all cells

Citric acid cycle

chemical cycle where oxidation of acetyl CoA from pyruvate is turned into CO2

Oxidative phosphorylation

production of ATP from redox reactions of ETC chain, 3rd major stage of cellular respiration

Substrate-level phosphorylation

enzyme catalyzed formation of ATP by direct transfer of p-group to ADP (from substrate)

Acetyl CoA

entry compound for citric acid cycle in cellular respiration formed from 2C fragment of pyruvate attached to a coenzyme

Ribulose 1,5-bisphosphate carboxylase oxygenase

Rubisco" - enzyme in plant chloroplasts, that fixes CO2 during photosynthesis

Reduction

The complete or partial addition of electrons to a substance involved in a redox reaction.

Regeneration of CO2 acceptor

carbon skeleton of 5 molecules of G3P are rearranged by spending 3 ATP; the RuBP is then ready to receive CO2 again

C3 Plants

plant that uses CC for initial steps that incorporate CO2 into organic compounds, forming 3C compound as first stable intermediate

C4 Plant

plants that use CC after reaction that incorporates CO2 and decreases photosynthetic output...generally occurs in hot environments; O2 ratio rises due to stomata closing

Photorespiration

metabolic pathway that consumes O2 and ATP, releasing CO2 into organic compounds, forming 3C compound as first stable intermediate

Bundle-sheath cells

type of photosynthetic cell in C4 plants arranged into tightly packed sheaths around the veins of a leaf

PEP Carboxylase

enzyme that adds CO2 to phosphoenolpyruvate (PEP) to form oxaloacetate in mesophyll cells of C4 plants prior to photosynthesis

CAM

crassulacean acid metabolism" adaptation for plants in arid conditions; stomata open at night for CO2 to be made into organic acids (no light), and close during day (light)

CAM plant

plants that use "crassulacean acid metabolism" in arid conditions. Here, CO2 enters plant @ night (stomata open) and are turned into organic acids, which then release CO2 for the CC during the day (stomata closed) store organic acids in vacuole

ubiquinone

first electron transfer agent in ETC

cytochrome c

enzyme (protein) with iron that is component of ETC in mitochondria and chloroplast of eukaryotic cells and plasma membrane of prokaryotic cells

plastoquinone

pq" first electron transfer agent in light reaction

plastocyanin

pc" second electron transfer agent in light reaction

ferodoxin

fd" third electron transfer agent in light

flavin mononucleotide

fmn" protein where NADH comes in ETC

iron sulfur protein

fes" protein where FADH2 enters in ETC