Life substances-part 2

Proteins: contain C, H, O,N, & sometimes S Multipurpose molecules 2006-2007

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

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

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

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

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

Amino acids can be linked by peptide bonds Cells link amino acids together by dehydration synthesis The bonds between amino acid monomers are called peptide bonds PEPTIDE BOND Dehydration synthesis Dipeptide Amino acid Amino acid

For proteins: SHAPE matters! Proteins fold & twist into 3-D shape 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 unfolding proteins = “denature” temperature pH unfolded “denatured” In Biology, it’s not the size, it’s the SHAPE that matters! folded

Enzymes (SEE SEPARATE LECTURE.) Enzymes are important proteins found in living things. An enzyme is a protein that speeds up the rate of a chemical reaction. (SEE SEPARATE LECTURE.)

Nucleic acids A nucleic (noo KLAY ihk) acid is a complex biomolecule that stores cellular information in the form of a code. 1. DNA (deoxyribonucleic acid) contains the instructions used to form all of an organism’s proteins. 2. RNA (ribonucleic acid) forms a copy of DNA for use in making proteins. They ultimately control the life of a cell

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

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

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

DNA Double strand twists into a double helix A pairs with T A :: T Weak hydrogen bonds between nitrogen bases join the 2 strands A pairs with T A :: T C pairs with G C :: G the two strands can separate when our cells need to make copies of it weak hydrogenbonds It’s a helix or B sheet within a single region. Can have both in one protein but a specific region is one or another