cell bio exam 1

Robert Hooke

first to identify cells in 1665; English scientist

cell theory

cells are the universal building blocks of all living things

Matthis Schleiden and Theodore Schwann

co-founded the cell theory in 1839

when was the electron microscope invented?

1930s

when was the light microscope invented?

1400-1600

what elements make up 96% of all living matter?

C, H, O, N

trace elements

elements that are needed only in small amounts

chemical bond

weak or strong electrical attraction that holds atoms in the same vicinity

molecule

grouping of two or more atoms held together by chemical bonds

valence electrons

electrons in the outermost shell; most important in determining an atom’s chemical behavior/properties

valence shell

the outermost shell of an atom

atoms in the same column __?

have similar chemical behaviors

atoms with completed valence shells __?

are inert and do not readily react with other atoms

atoms with incomplete valence shells __?

interact in a way to fill each partner’s shells

covalent bonds

formed when atoms share electron

ionic bonds

formed when atoms transfer electrons

strongest types of chemical bonds?

ionic and covalent

nucleotide

• 5-carbon sugar

• phosphate group

• nitrogen-containing base

nucleoside

• 5-carbon sugar

• nitrogen-containing base

steroids

lipids characterized by a carbon skeleton of four fused rings

cholesterol is an example of a(n)

steroid

pyrimidine base

single ring compounds (C, U, T)

purine bases

double ringed compounds (A and G)

phosphodiester bond

bond between 5’ phosphate group in sugar and 3’ hydroxyl group in adjacent nucleotides (DNA)

activated carrier

 a molecule that carries energy in one or more of its bonds

ATP

stores adn transfers energy within; base is adenosine and sugar is ribose

coenzyme A (CoA)

important in cellular respiration

cyclic AMP

signaling molecule in cells

phosphate group forms an intracellular connection (hence the cyclic)

• base is adenosine/adenine

• sugar is ribose

proteins

polymers made of amino acids subunits

titan

longest protein with 27,000 amino acid units

amino acids

• amino group

• carboxyl group

• hydrogen and R group connected to central/alpha carbon

R group/side chain

identifying factor of an amino acid

polypeptides

polymers of amino acids

our cells have a pH of __?

7.3

are amino acids charged?

• yes they are ionized

• positive amino group and negative carboxyl

glycine

• simplest amino acid

• R group consists of one hydrogen

#_ of possible different proteins formula

20^n

• n = number of amino acids in polypeptide

families of amino acids

• acidic

• basic

• uncharged polar

• nonpolar

acidic chains

aspartic acid

glutamic acid

• contain carboxyl group in side chains

basic side chains

lysine

arginine

histidine

• contain amine groups

uncharged polar side chains

asparagine (amide)

glutamine (amide)

serine (hydroxyl)

threonine (hydroxyl)

tyrosine (hydroxyl)

nonpolar side chains

alanine
phenylalanine

valine

leucine

isoleucine

proline

methionine

tryptophan

glycine

cysteine

acids

• release protons when dissolved in water

• increase H+ concentration

• decrease pH

bases

• accept protons when dissolved in water

• reduce H+ concentration

• increase pH

pH scale

acidity of a solution is defined by concentration of hydronium ions/protons

peptide bond

• amide linkage between amino acids

• link between hydroxyl group of one and amino group of another

what makes a protein functional?

the folding

hydrogen bonding in amino acids

occurs between carboxyl group and amino group

electrostatic attractions

negative acidic carboxyl group interacts with basic side chain of amine group

hydrophobic protein interaction

nonpolar sidechains/hydrophobic are folded inside the protein to avoid contact with water

hydrophilic

• likes water

• polar

hydrophobic

• dislikes water

• nonpolar

levels of protein organization

• primary

• secondary

• tertiary

• quaternary

DNA domains

• segments of a polypeptide that can fold independently

• have individual functions

• made up of 40-350 amino acids

binding site

site on a polypeptide or proteins surface that interacts with another molecule through noncovalent bonding

hydration shell

sphere of water molecules around each dissolved ion of ionic compounds in water