Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
90 Cards in this Set
- Front
- Back
Ability to promote change or do work
|
Energy
|
|
energy associated with movement
|
Kinetic
|
|
energy due to structure or location
|
Potential
|
|
energy in molecular bonds
|
Chemical energy
|
|
conservation of energy, energy cannot be created or destroyed and can be transformed from one type to another
|
First law of thermodynamics
|
|
Transfer or transformation of energy from one form to another increases entropy or degree of disorder of a system
|
Second law of thermodynamics
|
|
involve an increase in entropy
|
Energy transformations
|
|
unusable energy, a measure of the disorder that cannot be harnessed to do work
|
Entropy (S)
|
|
reactions occur without input of additional energy and are not necessarily fast
|
Spontaneous
|
|
ΔG<0 or negative free energy change, is spontaneous
|
Exergonic
|
|
ΔG>0 or positive free energy change, requires addition of free energy and are not spontaneous
|
Endergonic
|
|
Glucose + phosphate → glucose-phosphate + H2O
ΔG = +3.3 Kcal/mole |
endergonic reaction
|
|
ATP + H2O → ADP + Pi
ΔG = -7.3 Kcal/mole |
exergonic reaction
|
|
Glucose + ATP → glucose-phosphate + ADP
ΔG = -4.0 Kcal/mole |
Coupled reaction:exergonic
|
|
agent that speeds up the rate of a
chemical reaction without being consumed during the reaction |
Catalyst
|
|
protein catalysts in living cells
|
Enzymes
|
|
RNA molecules with catalytic
properties |
Ribozymes
|
|
Initial input of energy to start reaction
|
Activation energy
|
|
Activation energy allows molecules to get close enough to cause
|
bond rearrangement
|
|
2 common ways of overcoming activation energy
|
heat and enzymes
|
|
Straining bonds in reactants to make it easier to
achieve transition state |
Lowering activation energy
|
|
location where reaction takes place
|
Active site
|
|
reactants that bind to active site
|
Substrate
|
|
formed when enzyme and substrate bind
|
Enzyme-substrate complex
|
|
plateau where nearly all active sites
occupied by substrate |
Saturation
|
|
velocity of reaction near maximal rate
|
Vmax
|
|
substrate concentration at which velocity is
half maximal value |
Km
|
|
Km is also called
|
Michaelis constant
|
|
there are ___ types of Inhibition
|
2
|
|
Molecule binds to active site and inhibits ability of substrate to bind, Km increases- more substrate needed
|
Competitive inhibition
|
|
Lowers Vmax without affecting Km and Inhibitor binds to allosteric site- not active site
|
Noncompetitive
|
|
small molecules permanently attached to the enzyme
|
Prosthetic groups
|
|
usually inorganic ion that temporarily binds to enzyme
|
Cofactor
|
|
organic molecule that participates in reaction but left unchanged afterward
|
Coenzyme
|
|
Most enzymes function maximally in a ______ range of temperature and pH
|
narrow
|
|
found in all living organisms
|
Ribonuclease P (Rnase P)
|
|
1 RNA and 1 protein subunit
|
Ribonucleoprotein
|
|
accelerates rate without being altered
|
True catalyst
|
|
a series of chemical reactions in which each step is coordinated by a specific enzyme
|
metabolic pathways
|
|
Result in breakdown and are exergonic
|
Catabolic pathways
|
|
Promote synthesis and are endergonic and must be coupled to exergonic reaction
|
Anabolic pathways
|
|
Breakdown of reactants and used for recycling
|
Catabolic reactions
|
|
A molecule such as ATP or NADH that stores energy and is used to drive endergonic reactions
|
energy intermediate
|
|
Used to obtain energy for endergonic reactions
|
Catabolic reactions
|
|
Substrate-level phosphorylation and Chemiosmosis
|
2 ways to make ATP
|
|
Enzyme directly transfers phosphate from one molecule to another molecule
|
Substrate-level phosphorylation
|
|
Energy stored in an electrochemical gradient is used to make ATP from ADP and Pi
|
Chemiosmosis
|
|
Also known as Oxidation-Reduction reactions
|
Redox
|
|
Removal of electrons
|
Oxidation
|
|
Addition of electrons
|
Reduction
|
|
Electron removed from one molecule is added to another
|
Redox reaction
|
|
Oxidized to make ATP and can donate electrons during synthesis reactions
|
NADH
|
|
Electrons removed by oxidation are used to
create ________ like NADH |
energy intermediates
|
|
are biosynthetic reactions and make large macromolecules or smaller
molecules not available from food |
Anabolic reactions
|
|
Each ATP undergoes _______ cycles of hydrolysis
and resynthesis every day |
10,000
|
|
Particular amino acid sequences in proteins
function as |
ATP-binding sites
|
|
On average, _____ of all proteins bind ATP
|
20%
|
|
Turn on or off genes
|
Gene regulation
|
|
Cell-signaling pathways like hormones
|
Cellular regulation
|
|
product of pathway inhibits early steps to prevent overaccumulation of product
|
Feedback inhibition
|
|
Feedback inhibition
|
Biochemical regulation
|
|
Biochemical regulation, Cellular regulation, and Gene regulation
|
Regulation of metabolic pathways
|
|
time it takes for 50% of the molecules to be broken down and recycled
|
Half-life
|
|
Most large molecules exist for a relatively ____period of time
|
short
|
|
All living organisms must efficiently use and _____ organic molecules
|
recycle
|
|
Expression of ______ allows cells to respond to changes in their environment
|
genome
|
|
made when needed and are broken down when they are not
|
RNA and proteins
|
|
Conserve energy by degrading mRNAs for proteins no longer required and remove faulty copies of mRNA
|
mRNA degradation important
|
|
Multiprotein complex uses exonucleases
|
Exosome
|
|
Enzyme that cleaves off nucleotides from the end of the RNA
|
Exonuclease
|
|
Lysosomes contain _______ to break down proteins, carbohydrates, nucleic acids, and lipids
|
hydrolases
|
|
recycling worn out organelles
|
Autophagy
|
|
a double membrane structure enclosing cellular material destined to be degraded , produced by the process of autophagy
|
Autophagosome
|
|
the primary pathway for protein degradation in archaea and eukaryotic cells is via a protein complex called
|
proteasome
|
|
enzymes that cleave the bonds between adjacent amino acids
|
proteases
|
|
sum total of all chemical reactions that occur within an organism
|
metabolism
|
|
process in which one or more substances are changed into other substances
|
chemical reaction
|
|
study of energy interconversions
|
thermodynamics
|
|
total energy
|
enthalpy (H)
|
|
usable energy-amount of available energy that can be used
|
free energy (G)
|
|
molecule that is a common energy source for all cells
|
ATP
|
|
process by which a a phosphate is directly transferred from ATP to glucose
|
phosphorylation
|
|
state in which the original bonds have stretched to their limit
|
transition state
|
|
enzymes recognize specific substrates
|
specificity
|
|
when substrate binds to an enzyme and the enzyme undergoes conformational changes that cause a tighter bind
|
Induced fit
|
|
degree of attraction between enzyme and its substrate
|
affinity
|
|
not active site
|
allosteric site
|
|
RNA molecule that catalyzes a chemical reaction
|
ribozyme
|
|
slowest step in a pathway
|
rate-limiting step
|
|
small protein in eukaryotic cells that directs unwanted proteins to a proteasome by its covalent attachment
|
ubiquitin
|