cell bio exam 1

What reaction joins monomers together?

Dehydration (condensation) reaction

What reaction breaks polymers apart?

hydrolysis reaction

Building molecules is called?

anabolism

Breaking molecules down is called?

catabolism

What do enzymes do?

speed up chemical reactions; enzyme

What do structural proteins do?

provide support/build structures

What do transport proteins do?

move substances in and out of cells

What do receptor proteins do?

recieve signals

What do defense proteins do?

Protect the body from foreign pathogens

How many amino acids are used to build proteins?

20

What determines amino acid properties?

R group

Which amino acid is not chiral?

Glycine

What are enantiomers?

isomers that are mirror images of each other

Which form is used in proteins?

L amino acids

Acidic amino acids?

aspartate, glutamate

Basic amino acids?

lysine, arginine, histidine

Nonpolar amino acids tend to be where?

protein interior

Polar amino acids tend to be where?

protein surface

What bond links amino acids?

peptide bonds

Is a peptide bond covalent?

yes

What end has the amino group?

N-terminus

What end has the carboxyl group?

C-terminus

Primary structure?

sequence of amino acids

Secondary structures?

alpha helix and beta sheet

2ndary Stabilized by?

hydrogen bonds

Tertiary structure?

3D folding of one polypeptide

Quaternary structure?

multiple polypeptide chains

example of quaternary structure

hemoglobin

Strongest bond in proteins?

disulfide bonds

What amino acid forms disulfide bonds?

Cysteine

What can denature proteins?

Heat, pH changes, salt

Miller-Urey experiment showed what?

Organic molecules can form abiotically

What amino acids were produced in miller-urey exp?

glycine and alanine

Which likely came first?

RNA

Why RNA first?

Stores information and acts as catalyst

Catalytic RNA is called?

ribozyme

What are liposomes?

Artificial membrane vesicles

why are liposomes important?

Model for protocells

Three domains?

Bacteria, Archaea, Eukarya

Prokaryotes include?

Bacteria and Archaea

Which have nuclei?

eukaryotes

Which have membrane-bound organelles?

Eukaryotes

Typical bacterial size?

1-5 micrometers

Typical eukaryotic size?

10-100 micrometers

Methanogens produce?

methane

Halophiles live where?

Salty environments

Thermacidophiles live where?

Hot acidic environments

Why can't cells become huge?

SA:V ratio decreases

Volume increases with?

Cube of length

Surface area increases with?

square of length

microvilli Function?

Increase surface area

microvilli Found where?

small intestine

Diffusion definition?

Movement high → low concentration

Diffusion Requires ATP?

No

Large molecules diffuse faster or slower?

Slower

Six types of work?

Synthetic, mechanical, concentration, electrical, heat, light

Synthetic work is?

Building molecules

Mechanical Work?

Muscle contraction

Concentration Work

Active transport

What creates membrane potential?

Ion movement

Production of light by organisms?

bioluminescence

GFP stands for?

green fluorescent protein

GFP used for

Tracking proteins

Phototroph?

Gets energy from sunlight

Chemotroph?

Gets energy from chemicals

Autotroph?

Organisms that make their own food

Heterotroph?

organism that obtains energy from the foods it consumes; also called a consumer

Oxidation?

loss of electrons

Reduction?

gain of electrons

OIL RIG?

oxidation is loss, reduction is gain

first law of thermodynamics

Energy cannot be created or destroyed

second law of thermodynamics

Every energy transfer or transformation increases the entropy of the universe.

Entropy?

A measure of disorder or randomness.

ΔG < 0?

spon

ΔG > 0?

nonspon

ΔG = 0

Equilibrium

What is a substrate?

Molecule enzyme acts on

Most enzymes are?

proteins

Activation energy?

Energy needed to get a reaction started

Transition state?

a high-energy intermediate state

What do catalysts do?

lower activation energy

Are catalysts consumed?

No

Do enzymes change ΔG?

No

Do enzymes change equilibrium?

No

What do enzymes change?

rate of reaction

Active site?

Binding/catalytic region

Substrate binds where?

Active site

Most common active-site amino acids?

Ser, His, Lys, Asp, Glu, Cys

Prosthetic group?

Tightly bound cofactor

Coenzyme?

organic cofactor

Coenzyme Often derived from?

vitamins

Why are enzymes specific?

because only specific substrate molecules fit into their active site

Oxidoreductases?

catalyze oxidation-reduction reactions

Transferases?

transfer functional groups

Hydrolases?

hydrolysis reactions

Lyases?

add groups to or remove groups from double-bonded substrates

Isomerases?

rearrangement of the structure of molecules

Ligases?

Join molecules

Vmax?

Maximum reaction rate

Km?

Substrate concentration at 1/2 Vmax