Section 1 Bio

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Nonpolar Amino Acids

PGVIPMALT proline, glycine, valine, isoleucine, phenylalalanine, methionine, leucine, tryptophan

Positive Feedback

a downstream product returns to activate an earlier enzyme (occurs less often than negative feedback)

Secondary Structure

*patterns of hydrogen bonds bewteen backbone amide (H) and carboxyl (O) groups

Alpha Helix

*usu right handed helix that twists clockwise & makes a complete turn every 3.6 AA

Polar Amino Acids

CTTAGS cysteine, threonine, tyrosine, asparagine, glutamine, serine

Denaturing Agents and Forces Disrupted

*urea - hydrogen bonds

Acidic Amino Acids

*glutamic acid (glutamate)

Denaturation

*when protein conformation is disrupted & protein loses most 2º, 3º, 4º structure, not 1º bc covalent bonds

Quaternary Structure

*formed when 2 or more polypeptide chains bind together, each referred to as a subunit

Movement of Products of Glycolysis to the Matrix

*outer mito mem: permeable to sm molecules & both pyruvate & NADH pass via facilitated diffusion through porin, a lg membrane protein

Residue

each amino acid in a polypeptide chain

Amylospectin

form of starch that resembles glycogen but has a different branching structure

Fatty Acids

*long chains of carbons (usu even #, 24 max in humans) truncated at one end by a carboxylic acid

Glycoproteins

proteins that have carbohydrate groups attached that are a component of cellular plasma membrane

Glycolipid

*amphipathic lipids with one or more carbs attached

Kreb's Cycle (Citric Acid Cycle)

*each turn produces: 1 ATP (via substrate level phosphorylation), 3 NADH, 1 FADH2

Hydrogen Bond

*intermolecular force that allows H2O to maintain a liquid state in cellular environment (most cpds as light as H2O would be gas at high body temp, 37ºC/98.6ºF

How do most cell absorb glucose?

facilitated diffusion

Steroids

*4-ringed lipids

Liver and Glucose

the liver regulates the blood glucose level so liver cells are one of few cell types capable of reforming glucose form glycogen and releasing it back into the bloodstream

Negative Feedback

*when a product downstream in a reaction series comes back and inhibits enzymatic activity in an earlier reaction

Substrate Level Phosphorylation

formation of ATP from ADP & inorganic phosphate using the energy form the decay of high energy phosphorylated compounds as opposed to the energy from diffusion

Positive Cooperativity

the first substrate to bind changes the shape of the enzyme allowing other substrates to bind more easily

Amylose

form of starch that is an isomer of cellulose and may be branched or unbranched and has the same alpha-linkages as glycogen

Zymogen

*proenzyme

Steps of the CAC

OXALOACETATE (+acetyl CoA) → CITRATE → ISOCITRATE → (CO2, NAD+→NADH) α-KETOGLUTARATE → (CO2, NAD+→NADH) SUCCINYL CoA → (GDP→GTP) SUCCINATE → (FAD → FADH2) FUMARATE → MALATE → (NAD+→NADH) *repeat

Irreversible Inhibitor

bind covalently (a few noncovalently) to enzymes and disrupt their function, tending to be highly toxic

Nucleic Acid

polymer of nucleotides joined by phosphodiester bonds between the phosphate group of one nucleotide and the 3rd carbon of the pentose in the other nucleotide (DNA, RNA)

Acetyl CoA

*coenzyme

Reaction Rate and pH

enzymes function within specific pH ranges and denature when the pH is too far from the optimal pH (graph is like a normal curve)

Michaelis Constant (Km)

*the substrate concentration at which the reaction rate is equal to 1/2 Vmax

Starch

*carbohydrate polymer for storage in plants

Phosphatase

an enzyme which dephosphorylates something

Saturation Kinetics

*as relative concentration of substrate increases, the rate of rx also increases, but to a lesser and lesser degree until a max rate (Vmax) is reached

Prosthetic Groups

coenzyme that remains covalently bound to the enzyme throughout the reaction and emerges unchanged (e.g. heme)

Globular Tubulin

polymerizes under the right conditions to become a structure protein and makes up microtubules, the component of eukaryotic flagella and cilia

Primary Structure

number and sequence of amino acids, including the locations of disulfide bonds between cysteines