Biology CLEP Modern States

compound

2+ different elements combined in a fixed ratio

molecule

2+ same or different elements combined in fixed ratio

valence shell

outermost electron shell

valence electrons

electrons in the outermost shell

electrons are most reactive when

the valence shell is incomplete

Chemical bonds

the attractive forces that hold atoms together

covalent bond

a bond formed when atoms share one or more pairs of electrons

nonpolar covalent bond

A type of covalent bond in which electrons are shared equally

polar covalent bond

unequal sharing of electrons, creates partial charges (poles)

ionic bond

strong electrical attraction between two oppositely charged atoms or groups of atoms (cation to anion)

Cation

A positively charged ion

Anion

A negatively charged ion

hydrogen bond

weak attraction between a hydrogen atom and another atom

1st law of thermodynamics

Energy cannot be created or destroyed

2nd law of thermodynamics

Energy cannot be changed from one form to another without a loss of usable energy

endothermic reaction

A reaction in which energy is absorbed

exothermic reaction

A reaction that releases energy in the form of heat

Properties of water

cohesion, adhesion, excellent solvent, solid is less dense than liquid, specific heat, surface tension

Adhesion

attraction between molecules of different substances

Cohesion

Attraction between molecules of the same substance

why can life be sustained in water when the temp is below freezing?

solid is less dense than liquid, ice rises

properties of acids

dissolve in water, increase H+ ion concentration in solution. Smaller # on pH scale

properties of bases

dissolve in water, decrease relative H+ ion concentration in solution. higher # on pH scale

Buffer

compound that prevents sharp, sudden changes in pH. generally brings it to neutral (7)

organic molecules

carbon-based molecules. singular=monomers

plural=polymers

Carbohydrates

C+O+H

monomer= monosaccharide (glucose)

polymer= polysaccharide (starch)

Lipids

fats and oils

hydrophobic

Proteins

Chains of amino acids

monomer= amino acid

polymer= polypeptide (proteins)

peptide bond

Bonds that connect amino acids.

protein functions

enzyme catalysis, defense, transport, support, motion, regulation, storage

neucleic acid

DNA and RNA

monomer= nucleotide

Neucleic acid function

information storage

Nucleotide

monomer of nucleic acids made up of a phosphate group, a nitrogen base, and a sugar (deoxyrobose or ribose)

Adenine

Thymine/Uracil

Cytosine

Guanine

what bonds O and H in a water molecule?

nonpolar covalent bond

Microtubules

Spiral strands of protein molecules that form a hollow tubelike structure.

form mitotic spindle and keep shape

intermediate filaments

Threadlike proteins in the cell's cytoskeleton that are roughly twice as thick as microfilaments

keep organelles in place

microfilaments

Fine, threadlike proteins found in the cell's cytoskeleton. form cellular cortex

lysosome

An organelle containing digestive enzymes

peraxisome

metabolizes waste

Cytoplasm

A jellylike fluid inside the cell in which the organelles are suspended

cell membrane

the selectively permeable lipid membrane surrounding the cytoplasm of a cell.

Nucleus

Control center of the cell

stores and protects DNA, makes RNA and ribosomes

Ribosomes

protein synthesis

made of RNA and Proteins

protein synthesis

The creation of a protein from a DNA template.

Endoplasmic Reticulum (ER)

A cell structure that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another.

makes lipids

detoxing

Golgi apparatus

modifies, packages, stores, and transports lipids made by Smooth ER

Mitochondria

Powerhouse of the cell

Chloroplast

Site of photosynthesis

Meiosis

forms 4 haploid cells

Meiosis I

same as mitosis

Prophase 1, Metaphase 1, Anaphase 1, Telophase 1, Cytokinesis

Meiosis II

Meiosis 1 again.

Prophase 2, Metaphase 2, etc.

end up with 4 haploid (1n) cells

Watson and Crick

Developed the double helix model of DNA.

Process of Replicating DNA

1. enzyme Helicase breaks nucleotide bonds, unwinding double helix

2. enzyme DNA polymerase reads sequence of nucleotides on DNA strand

3. Polymerase builds new strand by matching nucleotides (A to T, C to G)

4. 2 DNA strands :)

Mutation

A change in a gene or chromosome.

Substitutions-wrong nucleotide (A instead of C, etc)

Frameshifts-extra nucleotide added/essential one deleted

gene

A segment of DNA on a chromosome that codes for a specific trait

Transcription

synthesis of an RNA molecule from a DNA template

DNA to RNA

Translation

sets of 3 nucleotides on mRNA, form codons

Codon

three-nucleotide sequence on messenger RNA that codes for a single amino acid. complimentary to anticodons (A to U, etc.)

Ribosomes match codons to anticodons. add amino acids=proteins

structural genes

genes that code for proteins

regulatory genes

code for regulatory proteins

regulate growth, development, start/stop transcription of certain genes

bacterial genes

no nucleus

DNA changed easily, quickly become resistant to medication

Transduction

viruses transfer genes between prokaryotes

Transformation

Bacteria take DNA right from environment

Viruses

Viruses can only reproduce inside host cells, and they damage the cell when they do this

have own DNA

Virus structure

DNA or RNA molecule with a protein coat for protection, the shape is created by its protein coat

some have enzymes

viral infection

1. Invades cell

2. Inserts genetic material

3. Viral genes direct host cell to make more virus parts

4. Virus multiplies

5. Mature virus leaves, rupturing membrane (kills cell)

what part of the cell membrane is fluid and can move past other membrane components?

lipids and proteins

hypotonic cell

loses water

what limits animal cell growth?

ratio of cell surface to cell volume

how do neurotransmitters enter the synapse?

exocytosis

Cytoskeleton

A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement. centromere is in its "family"

microfilaments help support

cell wall

strong, supporting layer around the cell membrane in some cells composed of cellulose, pectin, and chitin

centrosomes

Microtubule-organizing centers that help to form and organize the mitotic spindle during mitosis.

Microtubules are largest filaments

Intermediate filaments are durable

Vesicles

sacs made of membrane that can fuse with another cell's membrane

Vacuole

A sac inside a cell that acts as a storage area

passive transport

diffusion across a membrane requiring only the random motion of molecules with no energy expended by the cell

active transport

Energy-requiring process that moves material across a cell membrane. requires "doorway" protein

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration. passive transport.

Osmosis

diffusion of water

bulk transport

endocytosis and exocytosis

Endocytosis

entering the cell through vesicles

Exocytosis

exiting the cell through vesicles

prokaryotic cell

Bacteria and Archaea

no nucleus

unicellular

eukaryotes

animals, plants, fungi, protists

have cell membrane, organelles, DNA

uni or multicellular

activation energy

Energy needed to get a reaction started

Enzymes

proteins that act as biological catalysts

only function in living cells

Substrate

A specific reactant acted upon by an enzyme

active site

A pocket or groove on the surface of the enzyme.

where the substrate reacts

Coenzymes

enzyme helpers

usually vitamins

Cosubstrates

detachable coenzymes

organic

prosthetic group

permanent coenzyme

organic

inorganic cofactors

metal ions

organic cofactors

coenzymes

Inhibitor

molecule that binds to a protein (usually an enzyme) and keeps it from functioning by inhibiting substrate reaction

can change active site shape

Denaturation

change in enzyme shape that makes it not work

regulation

cell controls the action of its own enzymes

can use inhibitors

controls active site shape

cellular respiration

converting food (glucose) into energy (ATP)

steps of cellular respiration

1. Glycolysis

2. Pyruvate Oxidation

3. citric acid cycle

4. Electron Transport Chain