2 What is a cell?A cell is the smallest structural and functional unit of an organism
3 Cell Theory Microscopic lenses discovery of cells Cell theory All living things are composed of cells and their productsNew cells arise from the division of older cellsCells are the basic building blocks of life
4 Challenge time!Can you think of something you would call “alive” that isn’t made of cells?
6 Cells Two major classes of cells Eukaryotic Prokaryotic Have many membrane bound compartments called organellesAnimals, plants, fungiProkaryoticHave no membrane bound compartmentsBacteria
7 Evolution of Cells Tree of life can be divided into 3 domains Bacteria/Archaea = prokaryotesEukarya = eukaryotesProkaryotic cells are older/more primitive
8 OrganellesEukaryotic cells contain membrane bound compartments called organellesEach organelle performs specific jobs to aid the overall function of the cell
9 Analogy time!If a cell were a factory, what would its organelles be?
10 Nucleus Region of the cell that contains the DNA Tightly coiled strands of DNA are called chromosomesNucleoplasm is fluid in the nucleus
11 NucleusHave you ever seen a nucleus before?Sure you have!
12 RecallThe nucleus stores DNA, which contains your genetic code. What instructions are contained in this genetic code?Why might you call the nucleus the brain of the cell?
13 Nuclear EnvelopeThe nucleus is surrounded by a double phospholipid bilayercalled the nuclear envelopeProteins form channels through these membranes called nuclear pores
14 Recall The cell membrane is a single phospholipid bilayer Why do you think the nuclear envelope is a double phospholipid bilayer?
15 Nucleolus Nucleolus = region of the nucleus Rich in RNA Ribosomes are produced hereThen travel out to the cytoplasm
16 Ribosomes We’ve studied these already What is the function of ribosomes?Genes get transcribed into mRNA copiesRibosomes translate mRNA into proteinsWhere do ribosomes fit in this scheme?
17 Structure of Ribosomes Ribosomes have 2 subunits, each containing protein and RNA
18 Nobel Prize time!Enzymes are molecules that catalyze, or speed up the rate of a chemical reactionMany proteins are enzymesEx: Digestive enzymes are proteins that speed up the rate of digestion of food molecules
19 Nobel Prize time!1989 – Sid Altman wins Nobel Prize in chemistry for showing that RNA can catalyze reactions tooDiscovered RNA component of ribosomesWhen RNA was removed from ribosomes, they could no longer perform their job RNA is involved in the function of ribosomes
20 Application Question Enzymes catalyze, or speed up, reactions. What reaction do ribosomes catalyze?
21 1/10/12 Objective: Finish exploring organelles Do Now: Take your matching quiz! (10 min-ish)Do Later: Active reading of section 3.4
22 Cytoplasm The region outside the nucleus is called the cytoplasm Contains many organelles
24 Cytoskeleton How do cells maintain their shape? Structural support from protein rods that are called the cytoskeletonMicrofilaments = actin polymersMicrotubules = tubulin polymersImaging microtubules with actin-Green Fluorescent Protein
25 Nobel Prize time!2008 – Nobel Prize in Chemistry awarded for discovery of Green Fluorescent ProteinNaturally occurring in jellyfishGene for GFP can be spliced into gene for a protein of interestMakes protein under study fluoresce.