AP Bio Quiz 2

Quiz: Tues.

carbohydrates monomer

• monosaccharide (ex: glucose, fructose)

• shape: carbon ring

carbohydrates components

carbon, hydrogen, oxygen (usually 1:2:1)

glycosidic bonds/linkages

alpha & beta

alpha linkage

all monomers are in the same direction (functional groups extending from the monomers all run on the same side, polymer has a helical shape)

alpha function

storage of energy

a. starch: used by plants to store energy, consumed by animals for energy

b. glycogen: used by animals to store energy (usually in liver and muscles)

beta linkage

• monomers alternate in their orientation (meaning the functional groups extending from the monomers alternate in their positions)

• polymer has relatively straight shape

beta function

structure of cells/organism, not digestible b/c enzymes used for breaking down starch do not recognize/use the molecule b/c of difference in shape

a. cellulose: used in plant cell walls

b. chitin: used in fungi cell walls and exoskeletons of arthropods

lipid monomer

glycerol + fatty acids (glycerol loses a hydrogen and fatty acid loses an OH to form fat molecule), fatty acid chains bound to a glycerol

lipid components

carbon, hydrogen, oxygen

triglyceride components

3 fatty acid chains bound to a glycerol

saturated fat

contain maximum number of attached hydrogens, no double bonds b/t carbons (produced by animals)

saturated fats double bonds

lack of double bonds allows for straighter fatty acid chains and thus closer packing of molecules, solid at room temperature/high melting points

unsaturated fats

contain at least one carbon-carbon double bond, which reduces the number of attached hydrogen atoms (produced by plants)

unsaturated fats double bonds

• cis double bond results in kinked shape to fatty acid, molecules cannot pack tightly together, liquid at room temp/low melting point

• trans double bond (AKA trans fats) results in more linear shape, acts more like a saturated triglyceride (high melting point), usually not naturally occurring (produced via hydrogenation process in creating many processed foods)

phospholipids components

• components: 2 fatty acid tails joined to a glycerol, which is joined to a phosphate group (which has another attached group that can vary)

hydrophyllic vs. hydrophobic phospholipids

• phosphate head is polar, hydrophyllic (attracted to water)

• fatty acid is non-polar, hydrophobic (not attracted to water)

phospholipid role in cells

• form a bilayer cell membrane (border b/t inside and outside of cell)

• fatty acid tails orient towards middle of bilayer and heads are exposed to the intra and extracellular solutions (which contain water)

steroid components

have 4 fused carbon rings with attached functional groups (vary b/t different steroids)

steroid examples

cholestrol, estrogen, testosterone

triglyceride diagram

phospholipid

steroid

nucleic acids monomer

nucleotide, sugar with attached phosphate and nitrogenous base

nucleotide components

carbon, hydrogen, oxygen, nitrogen, phosphorus

nucleic acids- DNA

• “deoxyribonucleic acid”

• sugar: deoxyribose

• nitrogen bases: adenine, thymine, guanine, cytosine

• directionality: two sides are antiparallel, run in opposite directions

nucleic acids- RNA

• “ribonucleic acid”

• structure: single-sided

• sugar: ribose

• nitrogen bases: adenine, uracil, guanine, cytosine

• role in cell: creation of proteins

nucleic acids- ATP

• “adenosine triphosphate”

• structure: single nucleotide w/ 3 attached phosphates

• role in cell: stored energy (energy is released by breaking off one of the phosphates)

protein monomer

amino acid:

• central carbon (alpha carbon attached to a carboxyl group on one side)

• an amino group on the opposite side

• a hydrogen

• an R-group (specific to the amino acid, 20 total amino acids)

amino acids forming polymers

when forming polymers the carboxyl group of one AA loses a hydroxide (OH) and the amino group of another AA loses a hydrogen (H), linking the two together at the now open bonding areas and forming water (dehydration synthesis rxn)

proteins components

all contain carbon, hydrogen, oxygen, and nitrogen (2 also contain sulfur)

R-groups

attached to central carbon, varies depending on amino acid, have different properties based on attached functional groups

R-groups polarity

• nonpolar: hydrophobic (generally lack OH or NH₂) orient towards inside of protein to avoid contact with water in intra or extracellular solution

• polar: hydrophilic (most contain OH or NH₂), orient towards exterior of protein

R-groups charge

charged: orient towards exterior of protein

a. basic/positive: have positively charged N component

b. acidic/negative: have negatively charged O component

R-groups- cystine

forms disulfide bridge with another cystine if available, only slightly polar so it’s sometimes found on the inside of the folded protein

primary structure

amino acid sequence, begins with exposed amino end, ends with an exposed carboxyl end

secondary

hydrogen bonding between the amino group of one AA and the carboxyl group of another causes different shapes: alpha helix + beta sheet

alpha helix

hydrogen bonding between every fourth AA in the chain, causes a curled/corkscrew shape, R-groups stick out from curls

beta pleated sheet

two or more segments of the polypeptide chain lie next to each other, hydrogen bonding holding them together, R-groups stick up or down from sheets

tertiary

folding of the polypeptide based on interactions between the R-groups

• polar can form hydrogen bonds with each other

• charged from ionic bonds with R-groups of the opposite charge

• non-polar cluster in the center, away from water

• cysteines form disulfide bridges (covalent bonds)

quaternary

some proteins are made of two or more polypeptide chains clumped into one larger protein, not all proteins have multiple polypeptide chains

denaturing

proteins can lose their shape and become inactive;

can be caused by change in:

• pH

• salinity

• temperature

• change in polarity of solution

folding (not well understood, still undergoing research)

• chaperonin is a protein molecule that helps protect the polypeptide chain from chemicals in the cytoplasm that could disrupt folding

• accumulation of misfolded proteins can lead to disease (associated with Mad cow, Alzheimers, Parkinsons, cystic fibrosis)