ap bio quiz unit 2B
enzyme
biological catalyst that speeds up the reaction by reducing the amount of activation energy required. The reaction may be spontaneous w/o the catalyst, but it would be very slow.
Denaturation
breaking down of quaternary, tertiary, and secondary structures. Ruins the shape of the protein, renders it useless. Causes: high temperatures, low pH
amino acids
building blocks of proteins. 20 different amino acids on earth. All amino acids have same backbone structure: amine group on one end, carboxyl group on the other end. The unique functional group side chains distinguish one amino acid from another.
DG
change in free energy between products & reactants
proteins
characterized by amine & carboxyl groups. Functions: metabolism, enzymes, structural components, regulatory molecules
dehydration synthesis
combining of monomers to create polymers. Water is created, as OH and H are removed from the monomers to create the bonds.
Nucleotide
consists of a phosphate group, sugar, and nitrogen base
organic molecules
contain skeleton structures of carbon with hydrogen and oxygen
chitin
contains nitrogen, found in fungi cell walls & arthropod exoskeletons
nucleic acids
macromolecules containing hydrogen, oxygen, nitrogen, carbon, and phosphorus
energy storage
one function of polysaccharides is as an ____________________ macromolecule that is hydrolyzed as needed.
Deoxyribose
pentose joined to the nitrogen base in dna
ribosomes
site of protein synthesis
complex carbohydrates
starches, cellulose, glycogen, chitin, lipids
competitive inhibition
substance that resembles the normal substrate competes with the substrate for the active site
primary structure of protein
the amino acid sequence of the polypeptide chain
functional groups
the components of organic molecules that are most commonly involved in chemical reactions
optimal conditions
the pH, temperature, and concentration under which the enzyme is most active & efficient
enzyme-substrate complex
A temporary complex formed when an enzyme binds to its substrate molecule(s).
metabolism building bonds
-dehydration or condensation synthesis -anabolic -stores energy -endergonic
metabolism breaking bonds
-hydrolysis -catabolic -releases energy -exergonic
Cholesterol
A lipid that forms an essential component of animal cell membranes and acts as a precursor molecule for the synthesis of other biologically important steroids. precursor of steroids (hormones), always characterized by four fused rings in a lipid hydrocarbon skeleton
endergonic reaction
A non-spontaneous chemical reaction in which free energy is absorbed from the surroundings. (photosynthesis)
negative feedback
A primary mechanism of homeostasis, whereby a change in a physiological variable that is being monitored triggers a response that counteracts the initial fluctuation.
exergonic reaction
A spontaneous chemical reaction in which there is a net release of free energy. (cellular respiration)
noncompetitive inhibitor
A substance that reduces the activity of an enzyme by binding to a location remote from the active site, changing its conformation so that it no longer binds to the substrate.
positive feedback
A type of regulation that responds to a change in conditions by initiating responses that will amplify the change. Takes organism away from a steady state.
Macromolecules
A very large organic molecule composed of many smaller molecules (carbohydrates, lipids, proteins, nucleic acid)
ATP (adenosine triphosphate)
An adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed. This energy is used to drive endergonic reactions in cells.
tertiary structure of protein
Defined by the hydrophilic and hydrophobic interactions between R groups of amino acid chains. disulfide bridges, van der waals, hydrogen bonds
Carbon covalent bonds
Octet Rule # 3 - Share electrons
Monosaccharides
Single sugar molecules
factors affect enzyme activity
Temperature -Extreme temperatures will denature the enzyme, rendering it inactive -Temperatures of enzymes or substrates affect activity •pH -Extreme low or high pH denatures enzyme and renders it inactive -Some enzymes have optimal pH •Concentration -Density of either enzyme or substrate will affect the activity
allosteric regulation
The binding of a regulatory molecule to a protein at one site that affects the function of the protein at a different site.
quaternary structure
The fourth level of protein structure; the shape resulting from the association of two or more polypeptide subunits.
activation energy
The initial input (cost) of energy required to begin catabolism. Amount of energy needed to destabilize the bonds of a large molecule. Catalysts reduce the amount of activation energy.
Isomers
Two different molecules that have the same chemical formula
EA
activation energy, required to start reaction
secondary structure of protein
alpha helix and beta pleated sheet
Carbohydrates
are characterized by H, OH, and Carbonyl Groups. immediate energy, structural components
cellulose
different bonding, every other glucose is flipped, form sheets, very stable, cannot be digested by humans
Mitochondria
double helix structure site
protease
enzyme that digests protein
starches
fairly long polymers of glucose, branched
synthesis
formation of polypeptide from singular amino acids. Peptide bond forms between the amine group of one amino acid and the carboxyl group of the other amino acid. They line up end-to-end with their side chains hanging off the side.
glycogen
glucose storage in animals; stored in livers
ringed monosaccharides
glucose, dextrose, fructose
Enantiomers
isomers that are mirror images of each other
lipids
long chain hydrocarbons, nonpolar, hydrophobic Functions: long-term energy storage, insulation, cell membranes