UCI Bio 93- Midterm 1

atoms

smallest unit of chemical elements

molecules

two or more atoms combined

compound

two or more elements combined in a fixed ration

C, O, H, N

... are 4 elements that make up 96% of all living matter

covalent bond

what is the strongest bond?

covalent

sharing of electrons by two atoms

ionic

transfer of electrons between two atoms

hydrogen bond

what is a weak bond?

hydrogen bond

the H atom forms one covalent bond and a second weaker bond with an atom in another molecules

nonpolar

equal sharing of electrons

(two of the same element)

polar

unequal sharing of electrons

has a charge

(water)

negative

what is the charge of O in water?

positive

what is the charge of H in water?

cohesion

interactions between water molecules

(H2O with H2O)

solvent

interactions between water and other molecules

4 bonds

what is the maximum amount of bonds that hydrogen can form?

15%

in room temperature of water what % is the maximum amount of bonds going to be made?

more acidic

when H+ concentration increases...

more basic

what H- concentration decreases...

hydrophilic

affinity for water

(polar and ionic bonds)

hydrophobic

repel water

(nonpolar covalent bonds)

buffers

chemical processes are sensitive to pH changes and resist change in the pH solution

7.4

the pH of human blood is...

carbonic acid and bicarbonate

what are the main buffers in blood?

right

response to a rise in pH in blood (becomes more basic)

left

response to a drop in pH in blood (becomes more acidic)

carbon atoms

building blocks for biological molecules

4 VE

how many VE does carbon have?

covalent bonds

how do functional groups join to the carbon skeleton?

hydroxyl

-alcohols

-polar

-dissolves organic compounds (like sugars)

carbonyl

-ketones (within skeleton)

-aldehydes (at the end of skeleton)

carboxyl

-is acidic

-weak acid

-hydroxyl+carbonyl

amino

-base

-animes

-can pick up H from surrounding solutions

amino and carboxyl

what functional groups make up an amino acid?

sulfhydryl

-thiols

-cross-linking of cysteines

-stabilizes protein structure

phosphate

-backbone for phospholipids

-negative charge

-hydrophilic

methyl

-expression of genes

-sex hormones (shape and function)

carbohydrates, nucleic acids, lipids, and proteins

what are the 4 types of macromolecules?

carbohydrates, proteins and nucleic acids

which macromolecules are made of polymers?

lipids

-diverse group of hydrophobic macromolecules

-built from two or more DIFFERENT small subunits

dehydration reaction

removal of water molecules to form a polymer (makes a bond)

hydrolysis

addition of water to polymers to break bonds

carbohydrates

sugars and their polymers

monosaccharide

single monomer, form rings in aqueous solutions

disaccharide

2 monosaccharides joined by glycosidic linkage

(covalent bond)

polysaccharides

polymers of 100s and 1000s of monosaccharides

(connected by glycosidic linkage)

starch and glycogen

what forms of energy storage are in plants and animals?

fats, phospholipids, and steroids

what are the 3 types of lipids?

ester linkages

what types of bonds are in fats and phospholipids?

saturated and unsaturated

what forms do fats come in?

saturated fats

-No C=C double bonds

-more dense

unsaturated fats

-C=C double bonds

carbohydrates

fuels cellular respiration

polyunsaturated fat

more than one unsaturated carbon bond

polyunsaturated fat

fat that reduces cholesterol in blood and lower the risk of heart problems

9

how many calories is in 1 gram of fat? (all fats)

phospholipids

glycerol+ two fatty acids+ phosphate group+ choline

-hydrophilic head

-hydrophobic tail

steroids

carbon skeleton with 4 rings and varying functional groups

cholesterol

molecules that stabilize membrane fluidity

proteins

-one or more polypeptide with specific 3D conformation

-support, storage, transport, signaling, receptors, movement, catalysis, defense

polymer of amino acids to polypeptide

what is the structure of proteins?

amino group, hydrogen and carboxyl

what are composed in the structure of amino acids?

r-group

variable side chain

covalent bond

what type of chemical bond joins a functional group to the carbon skeleton of a large molecule?

they release a water molecule

what happens when 2 monosaccharides join to make a disaccharide?

serine, threonine and tyrosine

what can be replaced by a phosphate group?

no

is a fatty acid a monomer?

peptide bond

bond that connects carboxyl and amino group to make amino acid

N terminus

what is the amino end of a polypeptide?

C terminus

what is the carboxyl end of a polypeptide?

primary structure

the amino acid sequence and its shape

secondary structure

hydrogen bonding in the backbone, makes fold and coils (alpha helix-coils) (beta pleated sheets-folds)

tertiary structure

dependent on 1st and 2nd, R group interactions

-disulfide bridges (strong)

-H bonds, ionic bonds, hydrophobic, & van der waals interactions (weak)

quaternary structure

-two or more polypeptides

-stabilized by interactions between the R groups

single base change in DNA and RNA and amino acid change in protein

sickle cell anemia is caused by

changes in shape of cell does not allow H to travel easily

what happens what there is a sickle cell anemia mutation?

pH, high salt concentration, and temperature

denaturalization

chaperone proteins

-promote proper folding and refolding by providing cell with proper environment

-found throughout the cell

ubiquitin

damaged proteins are tagged with this to be recycles

proteasome

where ubiquitin leads tagged proteins and gets chopped into proteins

DNA and RNA

what are the two types of nucleic acids

store and transmit hereditary information

what functions do nucleic acids perform?

pentose sugar, nitrogen base, and phosphate group

what make up a nucleotide monomer?

sugars, DNA has thymine, and RNA has uracil

what is the structural different between DNA and RNA?

purines

guanine and adenine are...

2

how many rings do purines have?

pyrimidines

cytosine, thymine, and uracil are...

1

how many rings do pyrimidines have?

phosphodiester linkage

for nucleotides

A-T because it has 3 hydrogen bonds

what DNA bond is stronger and why? (A-T or C-G)

DNA (nucleotides) to transcription to mRNA (nucleotides) to translation to protein (amino acids)

Information flow in cells

hydrogen bonds

the strands and bases of DNA are held by

lipids, proteins and carbohydrates (all MACROmolecules except for nucleic acids)

what is the plasma membrane composed of?

amphipathic

molecule has two domains (one hydrophobic/hydrophilic side)

forms the bilayer

what do lipids do in P.M.?

regulates traffic

what do proteins do in P.M.?

cell to cell recognition, glycoproteins and glycolipids

what do carbohydrates of in P.M.?

heads up, tails down

what is the direction of the phospholipids?

weak hydrophobic interactions?

what is the plasma membrane held together by?

cholesterol

stabilizes the membrane fluidity