Proteins Proteins Multipurpose molecules 2006 2007 Proteins Examples

Proteins

Proteins: Multipurpose molecules 2006 -2007

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

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

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

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

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

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

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

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 u unfolding proteins = “denature” u § temperature § p. H (acidity) In Biology, it’s not the size, it’s the SHAPE that matters! unfolded “denatured” folded

Nucleic acids: Information molecules 2006 -2007

Nucleic Acids Examples u DNA § Deoxyribo. Nucleic Acid u RNA § Ribo. Nucleic Acid RNA

Nucleic Acids § Function: u genetic material § stores information w genes w blueprint for building proteins n DNA RNA proteins § transfers information w blueprint for new cells w blueprint for next generation proteins

Genes (DNA) are needed to run bodies every day… to make you and me… to make new cells… to make babies! G T A A C G T C G A T C A

Nucleic acids § Building block = nucleotides nucleotide – nucleotide u 5 different nucleotides u u different nitrogen bases A, T, C, G, U sugar phosphate N base Nitrogen bases I’m the A, T, C, G or U part!

Nucleotide chains § Nucleic acids u sugar N base phosphate nucleotides chained into a polymer § DNA w double-sided w double helix w A, C, G, T § RNA w single-sided w A, C, G, U phosphate strong bonds sugar N base phosphate RNA

DNA § Double strand twists into a double helix weak bonds between nitrogen bases join the 2 strands § A pairs with T w A : : T weak bonds § C pairs with G w C : : G u the two strands can separate when our cells need to make copies of it u

Copying DNA § Replication copy DNA u 2 strands of DNA helix are complementary u § they are matching § have one, can build other § have one, can rebuild the whole

DNA replication § Copying DNA u pairing of the bases allows each strand to serve as a pattern for a new strand Newly copied strands of DNA

1953 | 1962 Watson and Crick … and others…

HELIX Let’s build some DNA!