Unit 3: Cells Remediation Standards BIO. 3 a-e

Cell Theory + Microscopes Standard BIO. 3a

The Cell Smallest basic unit of life Organism Organ System Organs Tissues CELLSCELLS Organelles Molecules Atoms: Smallest nonliving unit

The Cell Theory 1.All organisms are made up of cells 2.All existing cells are produced by other living cells 3.The cell is the most basic unit of life

Developing The Cell Theory Robert Hooke: first person to view cells Anton van Leeuwenhoek: created a more powerful microscope, looked at pond water Matthais Schleiden: All plants are made up of cells Theodor Schwann: All animals are made up of cells Rudolph Virchow: all cells come from preexisting cells

The Compound Light Microscope

Parts of the Microscope Eyepiece: contains the ocular lens Arm: supports microscope when carried Objective Lenses: lenses that are nearest the object being viewed Body Tube: connects the eyepiece to the objective lenses Coarse Adjustment Knob: Moves the stage up and down for focusing Fine Adjustment Knob: moves the stage slightly to sharpen image Stage: supports the slide Stage Clips: holds slide Diaphragm: regulates amount of light Base: supports microscope

To determine total magnification take the eyepiece magnification (usually 10x) and MULTIPLY it by the objective lens magnification (usually 4x, 10x, and 40x)

Prokaryotic vs. Eukaryotic Cells Standard BIO. 3b

Types of Cells Prokaryotic Cells First cells to evolve NO Nucleus Genetic information is suspended in the cytoplasm Singled-celled Example: bacteria Eukaryotic Cells Evolved from prokaryotes Nucleus and organelles; specialized structures that perform distinct processes within a cell Mostly Multi-cellular Example: plant and animal cells

Cell Organelles + Their Functions Standard BIO. 3c

The Cell Membrane Cell Membrane: a barrier that separates the cell from the external environment. Controls what enters and leaves a cell.

Cytoskeleton Cytoskeleton: a network of proteins that is constantly changing to meet the needs of a cell. Supports and shapes the cell. 3 Types of Cytoskeleton Fibers: 1.Microtubules: shape, organelle movement, division 2.Intermediate Filaments: cell strength 3.Microfilaments: movement and division

Ribosomes Tiny organelles that link together amino acids to form proteins Found primarily in the cytoplasm where most protein synthesis occurs

Nucleus Nucleus: storehouse for most of your genetic information, DNA. DNA contains genes that are instructions for making proteins.

Endoplasmic Reticulum ER: where lipids and proteins are synthesized Smooth ER: where lipid synthesis occurs; breaks down drugs and alcohol Rough ER: studded with ribosomes; where protein synthesis occurs

Golgi Apparatus Golgi Apparatus: proteins from the ER move to the Golgi and are changed or packaged. Some of these proteins remain in the cell and others are transported outside of the cell.

Mitochondria Mitochondria: convert food into usable energy, ATP. Contain their own DNA and ribosomes and are thought to be originally free-living prokaryotes that were taken in by larger cells.

Lysosomes Lysosomes: contain enzymes that break down damaged or worn-out cell parts. They also defend a cell from bacteria and viruses. Found primarily in animal cells.

Cell Wall Cell Wall: found in plants, fungi, and most bacteria; rigid layer surrounding the cell membrane that gives protection, support and shape to the cell.

Vacuole Vacuole: fluid-filled sac used to store water, food, ions, and enzymes. Animal cells contain many small vacuoles while plant cells usually contain 1 large central vacuole.

Chloroplast Chloroplast: carry out photosynthesis in plants; convert solar energy into food.

Plant Cells vs. Animal Cells How do plant cells differ from animal cells? 1.Cell Wall 2.Chloroplast 3.1 Large Vacuole

Cell Membrane + Transport Standard BIO. 3d+e

The Cell Membrane A barrier that separates the cell from the external (outside) environment. Controls what enters and leaves a cell. Made up of phospholipids, which have polar (water loving) heads, and nonpolar (water hating) fatty acid tails Membrane is also embedded with various proteins and cholesterol

Movement Across the Membrane Concentration Gradient: difference in the concentration of a substance from one location to another. Molecules want to move DOWN their concentration gradients, they want to move from areas of HIGH concentration to areas of LOW concentration HIGH Solute Concentration Low Solute Concentration

Passive Transport Passive Transport: Movement of molecules across the cell membrane without energy input from the cell. Two Types: ▫Diffusion: The movement of molecules in a fluid or gas from a region of high concentration to a region of low concentration ▫Osmosis: The movement of water molecules from a region of high concentration to a region of low concentration

Diffusion The solute molecules will continue to move across the membrane until they are evenly spaced throughout the solution, this is called dynamic equilibrium.

Osmosis High Water Concentration; Low Solute Concentration Low Water Concentration; High Solute Concentration Water moves from an area of high water concentration to an area of low water concentration

Osmosis in Blood Cells Tonicity: the ability of a solution to cause a cell to gain or lose water Isotonic: no net movement of water; stable environment Hypertonic: cell loses water; too many solutes in the surrounding environment Hypotonic: cell gains water; too many solutes within the cell

Facilitated Diffusion The diffusion of molecules across a membrane through transport proteins. This is still a type of passive transport because no energy is used by the cell.

Active Transport Active transport is powered by ATP, because molecules are moving against their concentration gradeints. (from low to high) Active transport occurs through proteins imbedded in the membrane

Types of Active Transport: Endocytosis and Exocytosis Endocytosis Moves things into the cell by engulfing vesicles Vesicle: small organelle that contains and transports materials within the cytoplasm. Exocytosis Moves things out of the cell by vesicles