Biochem - Macromolecules

includes: lipids, nucleic acids, proteins - refer back to labs and notes! i may make a video explaining the unit (for myself mostly), i'll post the link if i end up doing that

lipids

aka fats, NOT A POLYMER

monomer of a lipid

glycogen and fatty acids

What are lipids made of?

carbon, hydrogen, oxygen

glycerol

backbone of a lipid

hydrophobic

water-fearing

hydrophilic

water-loving

What are the three types of lipids?

triglycerides, steroids, and phospholipids

triglycerides (purpose)

energy storage and insulation

structure of a triglyceride

3 fatty acid chains and glycerol

What are the 2 types of triglycerides? (natural)

saturated fats and unsaturated fats

saturated fats

• the unhealthy fat

• single bonds between carbon atoms - makes the chain straight

• solid at room temp (because the chains are able to be packed together)

• comes mostly from animals

unsaturated fats

• the healthy fat

• has double bonds between carbons - creates kinks

• liquid at room temp

• mostly come from plants

• the double bond fills in space that the lack of hydrogen atoms created

What are the 2 types of unsaturated fats?

monounsaturated and polyunsaturated

What’s the difference between monounsaturated and polyunsaturated fats?

monounsaturated fats have one double bond, while polyunsaturated fats have multiple double bonds

trans fats

• most unhealthy fat

• manmade/artificial

• also known as hydrogenated oils

• provides better taste, texture, and longer shelf life

hydrogenation

adding hydrogen to unsaturated fats, turning it from a liquid to a solid (trans fats)

How do you know if a food has trans fats in them on a food label?

it will say “partially hydrogenated” on the ingredients list

cholesterol (purpose)

strengthen cell membranes

high density lipoproteins (HDL)

• transports cholesterol from the body to liver for breakdown and disposal

• the good type, need more of these

low density lipoproteins (LDL)

• transports cholesterol from the liver to the body

• the bad type, sticks to artery walls and can cause blood clots

unsaturated fats (relating to cholesterol)

raises HDL, lowers LDL

saturated fats (relating to cholesterol)

raises HDL, raises LDL

trans fats (relating to cholesterol)

lowers HDL, raises LDL

phospholipids (purpose)

make up the cell membrane

structure of a phospholipid

hydrophilic phosphate head, two hydrophobic fatty acid tails, glycerol molecule (connects head to tails)

phospholipid bilayer

the arrangement of phospholipids in the cell membrane; two layers with the tails facing towards each other

nucleic acids

complex molecules that store and transmit genetic information

What are nucleic acids made up of?

carbon, hydrogen, oxygen, nitrogen, phosphorous

monomer of nucleic acids

nucleotides

What are the 3 types of nucleic acids?

deoxyribonucleic acid (DNA), ribonucleic acid (RNA), adenosine triphosphate (ATP)

proteins (purpose)

involved in nearly every function of the body (structural, enzymes, transport, immunity)

What are proteins made up of?

carbon, hydrogen, oxygen, nitrogen, sometimes sulfur

monomer of proteins

amino acids

How many (common) types of amino acids are there?

20 types (10 from the body, 10 from food)

What makes each amino acid different?

the side R chain/group

peptide bonds

a type of covalent bond, specifically connects amino acids

What’s another name for protein?

polypeptide

structure of protein

folded structure

denaturation

the conditions of the protein changes, unraveling it (changing structure and losing its shape), therefore becoming nonfunctional

What causes denaturation?

• high temperatures (NOT COLD!)

• pH change

• salts

enzymes (purpose)

speeds up chemical reactions in the body (catalysts) by lowering the amount of activation energy needed

activation energy

the minimum amount of energy required in order for a chemical reaction to occur

What do enzymes USUALLY end in?

-ase

Can enzymes be reused?

yes

substrate

the substance the enzyme is working with (reactants)

active site

the place on the enzyme where substrates are inserted

product

what the substrate turns into after the enzyme finishes its job

How are enzymes specific?

each enzyme’s active site is specifically shaped for one unique substrate; can either build up or break down that substrate

induced fit

when the active site changes its shape TEMPORARILY to ensure a better fit and bind the substrate to itself

cofactors and coenzymes

enzyme helpers that can help bind the substrate to the active site

What are the steps of an enzyme at work?

1. substrate fits into active site of enzyme, forming enzyme-substrate complex

2. enzyme makes or breaks bonds to form new product

3. product released from enzyme

4. enzyme reused for the same reaction

What happens to the enzyme when it becomes denatured?

the shape of the active site changes, so the substrate cannot bind to it, making the enzyme non-functional

enzyme inhibitors

molecules that reduces the rate of a reaction and/or stops the enzymes from functioning properly; can be temporary or permanent

What are the 2 types of enzyme inhibitors?

competitive inhibitors and non-competitive inhibitors

competitive inhibitors

competes with substrates by binding to the active site first, blocking it

non-competitive inhibitors

binds to the enzyme at a different location (called allosteric site); this changes the shape of the active site, so the reaction can’t be catalyzed efficiently

examples of enzymes

protease, lipase, lactase, amylase, pepsin