Nucleic Acids, Proteins, & Gene Expression Honors Biology ch 4 & 8

Macromolecules are large organic carbon compounds Carbohydrates (Cell Energy) Lipids Proteins Nucleic Acids

Prior to 1900’s human civilization understood: Cells preformed various functions for life Proteins and nucleic acids existed

1941 Beadle and Tatum determined: Nucleic acids and proteins were linked And responsible for many cell functions

Monomer: Nucleotide 5-Carbon Sugar Phosphate Group Nitrogen Base Polymer: DNA/ RNA strands

Biological Functions: Storage of heritable information Helps make protein

Monomer: Amino Acid Carboxylic Acid (C & O) Amine Groups (N & H) Polymer: Polypeptide Chain 3D Structure of Protein Complex proteins fold

Biological Functions: Catalyze chemical reactions (enzyme) Build & repair tissues Transport & signal molecules

Human Tissues: Skin, Hair, Nails, Organs… Enzymes: make or break molecules

How are these molecules constructed in the biosphere

DNA  RNA  Protein

Organisms are a collection of traits!

Every cell of every organism has genetic information Entire set of DNA for an individual organism

Molecular process of converting DNA genes into a trait

Stage 1: Transcription Gene (section of DNA) is converted into mRNA code Stage 2: Translation mRNA, tRNA, rRNA link amino acids based on code Stage 3: Folding Polypeptide chain is folded into a specific protein shape

molgenetics/translation.swf molgenetics/translation.swf hill.com/olc/dl/120077/micro06.swf hill.com/olc/dl/120077/micro06.swf

One chemical changes into another: Reactant: chemical that enters rxn. Product: chemical produced by the rxn.

Not all rxns. occur spontaneously Activation energy: the energy required to start a reaction

Inside a cell Chemical reactions occur all the time These reactions are normally slow

Enzymes Speed up reactions by lower the activation energy

Complex 3D polypeptide chain (proteins)

Enzymes interact with substrates Make molecules Break molecules

Water breaks down eggs PEPSIN is an enzyme What is the substrate in the experiment? Which test tube will break down the egg fastest?

Lock and Key Model Enzymes must fit perfectly with substrate Therefore, one enzyme per substrate

Induced Fit Model: The active site of an enzyme binds to a substrate Enzyme changes shape to perform a biological rxn.

Amylase: in your mouth breaks down starch Peptidase in your stomach break down proteins Lipase: in your small intestine break down lipids There are over 2000 known enzymes in your body

1. Temperature: Increase in temp.  increase in enzyme speed Too much heat, the enzyme is denatured or destroyed 2. pH: Also denature the enzyme