lecture 10- proteins

proteins

large complex molecules/molecular complexes that do most of the work in the body

proteins responsilibities in the bodies

• structural

• enzymes

• transportation

• emergency energy source (4 cal per gram)

what is the monomer of protein?

amino acids

purpose of functional group (= r group) of amino acids

• determines chemical and physical properties

• structure determines the function of the group= r group determines structure

• proteins fold in water

what way do hydrophobic aa fold

inside to get away from water

what way do hydrophilic aa fold

outside towards water

polymer of protein

• peptides: poly=many, peptide= proteinn

• made up of a string of amino acids

primary structre of protein

string of amino acids connected together

secondary structure

forming alpha helices and beta pleted sheets

teritary structure

total 3d structure of folded protein

quaternanry structure

multiple 3d polypeptides folded togetehr

what are enzymes

• polypeptides

• protein that makes reactions easier to occur

• often end in ase

• lactase breaks apart lactose

hw do enzymes make reactions easier

they lower the energy needed to do reactions

what is an activation site

site where activation begins, enzymes have an active site

substrate (thing being reacted) must fit where?

must fit lock and key into active site

polypeptides: structural protein?

provide support and stiffness to otherwise squishy structures

most well known structural protein

collagen; fibrous protein that provide structure to cells, skin, bone, and connective tissue

how does collagen work in body over time

collagen is slowly lost over time, leading to wrinkles

• when eating collagen digested into individuals AAs

• peptide powders do not give you more collagen, just more AAs

• very little evidence these powders help skin, nails, hair

things you can to save you collagen

• sunscreen! all skin tones

• plenty of vitamin C

• do not smoke

• eat foods with copper and zinc

4 essential amino acids

lysine, trytophan, valine, histidine

valine r group

isoprophyl, -CH(CH3)2, hydrophobic

what are complete proteins

protein sources with all 9 essential amino acids. ex. dairly, meats, eggs are most complete, plus soy

meatless protein sources tend to be _____

incomplete.. ex. beans, lentils, mushroosm

what is denaturation

process of unfolding a protein caused by outside factors

causes of denaturation

• heat (ex. cooking egg whites, clear to white)

• salt

• acid (ceviche

• base

• intense mechanical agitation (merenge)

benefits of eating proteins

• makes you feel fuller for longer

• important for recovery and muscle growth

amount of protein per day

.36 per gram of body fat (can change based on sec, activity level, age, body goals)