Warm-up for 9/23 1. Polymers are made up of what? 2. What are 4 functions of lipids? 3. What are two types of fats? 1. Which of these are the better choice for your diet? 4. What type of lipid are cellular membranes made out of? 5. What are two types of Nucleic Acids? 6. What are 2 functions of Nucleic Acids? 7. How many nucleotide bases are there? Which ones are found in DNA? Which in RNA? 8. A pairs with ____ and _____ (in RNA). G :: ___

Proteins

Proteins: Multipurpose molecules

collagen (skin) Proteins insulin Examples  muscle  skin, hair, fingernails, claws  collagen, keratin  pepsin  digestive enzyme in stomach  insulin  hormone that controls blood sugar levels pepsin

Proteins  Function:  many, many functions  hormones  signals from one body system to another  insulin  movement  muscle  immune system  protect against germs  enzymes  help chemical reactions

Proteins  Building block = amino acid amino acid – amino acid – amino acid – amino acid – —N——N— H H H | —C— | C—OH || O variable group amino acids  20 different amino acids There’s 20 of us… like 20 different letters in an alphabet! Can make lots of different words

Amino acid chains  Proteins  amino acids chained into a polymer  Each amino acid is different  some “like” water & dissolve in it  some “fear” water & separate from it amino acid

Water-fearing amino acids  Hydrophobic  “water fearing” amino acids  try to get away from water in cell  the protein folds

Water-loving amino acids  Hydrophillic  “water loving” amino acids  try to stay in water in cell  the protein folds

pepsin For proteins: SHAPE matters! collagen  Proteins fold & twist into 3-D shape  that’s what happens in the cell!  Different shapes = different jobs hemoglobin growth hormone

It’s SHAPE that matters!  Proteins do their jobs, because of their shape  Unfolding a protein destroys its shape  wrong shape = can’t do its job  unfolding proteins = “denature”  temperature  pH (acidity) folded unfolded “denatured” In Biology, it’s not the size, it’s the SHAPE that matters!

Let’s EAT some Proteins!

Activities  demo raw egg vs. cooked egg  drop raw egg into boiling water, like egg drop soup  compare raw egg to hard-boiled egg  demo cheese-making with heated milk & vinegar  make yogurt

Carbohydrates

Regents Biology Carbohydrates: OH H H HO CH 2 OH H H H OH O Energy molecules

Carbohydrates  Building block molecules = sugar sugar - sugar - sugar - sugar - sugar sugars

sucrose Carbohydrates  Function:  quick energy  energy storage  structure  cell wall in plants  Examples  sugars  starches  cellulose (cell wall) glucose C 6 H 12 O 6 starch

Sugars = building blocks  Names for sugars usually end in  glucose  fructose  sucrose  maltose OH H H HO CH 2 OH H H H OH O glucose C 6 H 12 O 6 sucrose fructose maltose -ose

Building carbohydrates  Synthesis | glucose | glucose 1 sugar = monosaccharide 2 sugars = disaccharide | maltose mono = one saccharide = sugar di = two

Building carbohydrates  Synthesis | fructose | glucose 1 sugar = monosaccharide | sucrose (table sugar) 2 sugars = disaccharide How sweet it is!

BIG carbohydrates  Polysaccharides  large carbohydrates  starch  energy storage in plants potatoes  glycogen  energy storage in animals in liver & muscles  cellulose  structure in plants cell walls  chitin  structure in arthropods & fungi exoskeleton poly = many

Building BIG carbohydrates glucose + glucose + glucose… = starch (plant) glycogen (animal) energy storage polysaccharide

Digesting starch vs. cellulose starch easy to digest cellulose hard to digest enzyme

Cellulose  Cell walls in plants  herbivores can digest cellulose well  most carnivores cannot digest cellulose  that’s why they eat meat to get their energy & nutrients  cellulose = roughage  stays undigested  keeps material moving in your intestines

Different Diets of Herbivores Cow can digest cellulose well; no need to eat other sugars Gorilla can’t digest cellulose well; must add another sugar source, like fruit to diet

Helpful bacteria  How can cows digest cellulose so well?  BACTERIA live in their stomachs & help digest cellulose-rich (grass) meals