Cell Structure and Function

Cell Theory 1.All living things are made of one or more cells. 2.Cells are the basic units of structure and function in organisms. 3.All cells arise from existing cells.

Different Cell Types Prokaryote: Bacteria and Archaea Eukaryote: Plant, Animal, Protist, Fungi

Prokaryotes Bacteria and Archaea Before Nucleus – DNA not in a nucleus Small in size 0.1  m – 10  m Grow and divide rapidly Survive in wide range of environments

Eukaryotes Plants, Animals, Fungi, and Protists After nucleus – contains DNA in nucleus Complex – highly structured and specialized: membrane bound organelles Larger in size: 10  m  m

Prokaryote vs. Eukaryote

Eukaryotic Cell Organelles Let’s take a tour of the cell!

Cell Wall Plants ONLY Support, shape, and protect the cell Porous: O 2, H 2 O, CO 2

Cell Membrane Flexible Provides support, structure, and protection Semi- permeable: regulates what enters and exits the cell

Nucleus Houses the DNA Information for coding proteins and other molecules Pores on nuclear envelope

Nucleolus Inside the nucleus Ribosome assembly begins here

Ribosomes Made up of 2 subunits Proteins are assembled from RNA

Endoplasmic Reticulum Rough ER – Has ribosomes on it – Involved in protein synthesis: chemically modifies

Endoplasmic Reticulum Smooth ER – Synthesizes lipids and carbohydrates – Involved in detoxification of drugs

Golgi Apparatus Packages, modifies, ships proteins

Lysosome Breaks down lipids, carbohydrates, proteins in cell Involved in cell apoptosis (cell death)

Vacuole Mainly in plants Stores water, food, salts, proteins, and carbohydrates

Mitochondria Creates energy for the cell - ATP Contains its own DNA

Chloroplast Plants ONLY Creates food for cell through photosynthesis Contains its own DNA

Cytoskeleton Maintains internal structure within the cell Aids in movement/transportation within the cell

Cytosol Jelly like material where organelles are suspended Contains salts

Centrioles Structures that aid in cell division

Cell Analogy – “The Office” Cell wall – Outside walls Cell membrane – Security Guard – Hank Nucleus – Corporate – Jan and David Wallace Nucleolus – The Boss – Michael Scott Ribosomes – Sales Team – Jim, Dwight, Phyllis, and Stanley Rough ER – Client Relations – Creed Smooth ER – HR – Toby Golgi Apparatus – Warehouse workers – Darryl Lysosome – Cleaning Ladies Vacuole - Warehouse Mitochondria – Accountants – Oscar, Angela, and Kevin Cytoskeleton – Internal walls Cytosol – Air

Cell Songs Example 1: Cell SongCell Song Example 2: Cell RapCell Rap

Microscopy Scientists use microscopes to study cells. Without microscopes we would not even know cells existed! Robert Hooke : termed “cell” Anton Van Leeuwenhoek: advanced scopes and single – celled organisms

Microscope Characteristics Micrographs: images produced by microscope Magnification: the quality of making an image larger than its actual size. Resolution: a measure of the clarity of the image

Types of Microscopes Compound Light – Living or dead specimen – This is what we will use! Scanning Electron (SEM) – Dead specimen – Produces a 3D image Transmission Electron (TEM) – Dead specimen – Useful to view internal structures

Parts of Compound Light Microscope Arm Base Coarse Adjustment Diaphragm Fine Adjustment Objective Lenses Ocular Lens Light Stage Stage Clips

Parts of Compound Light Microscope Arm: Supports ocular lens and connects to stage. Base: bottom of the base used to support the scope. Coarse adjustment: Knob used to adjust the focus of the image. Use this on low power then change to high power and use fine adjustment. Fine adjustment: Knob used to adjust the resolution of the image. Use this when looking through high power.

Parts of a Compound Microscope Diaphragm: Used to vary the intensity of the light. Adjust brightness and clarity of the image. Objective Lenses: These magnify the image you are viewing. They range from low to high power (10x-40x). Ocular Lens: This is the eyepiece to view the image through. It magnifies the image 10x.

Parts of a Compound Microscope Light: This allows you to view the image on the slide. Stage: This is where you place the slide in order to view it under the objective lenses. This moves up and down in order to resolve the image through the lenses. Stage Clips: These hold the slide in place while being viewed under the objective lenses.

Surface Area: Volume Ratio