NAME_________________________________________ PERIOD__________
6th Six weeks notes 2015
CELLS
Cell
Theory
 All organisms are made of cells
Microscope
 A device with one or more lenses that enlarges the image of
 The cell is the basic unit of organization in organisms
 All cells come from other cells through either mitosis or meiosis
something
Prokaryotic vs. Eukaryotic
Prokaryotic
Cells
 Do NOT have a nucleus
 Genetic information just “floats” in the cytoplasm
 Only unicellular organisms
 Example – bacteria
Eukaryotic
Cells
 DO have a nucleus
 Have many different organelles
 Can be a unicellular or multicellular organism
 Example – plant & animal cells
Organelles
 Tiny structures within the cell that each carry out a certain function
CELL DIAGRAMS
Animal Cell
Plant Cell
Organelles found in BOTH Plant & Animal Cells
Cell
 Outer covering of the cell
Membrane
 Controls the movement of substances into and out of the cell
 Made of lipids (fats)
Osmosis
 Movement of water across the cell membrane
Diffusion
 Movement of other substances, such as oxygen, across the cell
Cytoplasm
 Jelly-like substance that cells are filled with
Nucleus
 Brain of the cell
 Does not require energy
membrane
 Substances move based on the concentration inside the cell vs.
outside the cell (move from higher to lower)
 Does not require energy
 Controls all of the cell’s activities
 Contains the DNA
Mitochondria
 Produces energy for the cell by breaking down food
Ribosomes
 Make proteins for the cell
 Usually found just outside the nucleus attached to the
endoplasmic reticulum
 Stores water and other waste materials
Vacuoles
 MUCH LARGER in plant cells
 Helps plant cells to maintain their SHAPE
Organelles ONLY found in Plant Cells
Cell Wall
 Tough rigid outer covering that protects plant cells and gives
Chloroplast
 Uses sunlight, water and carbon dioxide to make food
them shape
 Made of cellulose
 Give plants their green color
CELL REPRODUCTION:
Mitosis
vs.
Meiosis
Parent Cell
Daughter Cells
Mitosis
 Parent cell makes a COPY of itself
 Both daughter cells have the same exact DNA
 For unicellular organisms, mitosis is used for asexual
reproduction
 For multicellular organisms, mitosis is used for GROWTH
Meiosis
 Parent cell divides TWICE
 Parent cells genes are shuffled around
 FOUR daughter cells each have only HALF the parents genes
 For multicellular organisms, this form of sexual reproduction
creates genetically UNIQUE offspring
Organic vs. Inorganic Compounds
Organic
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Inorganic
Come from living organisms
Involved in all biochemical activities
MUST contain carbon atoms bonded to other Carbon atoms
Can also contain Hydrogen, Oxygen, Sulfur, Phorsphorus and
Nitrogen
Ex: Sugars-C12H22O12, Vitamins-C29H50O2, Hormones-C19H28O2,
Amino Acids-C6H12N2O4S2, Nucleic Acids-C6H14N2O2

DO NOT come from organisms
 Can contain any elements
 Any substance that is NOT organic
 Ex: Water-H2O, Carbon Dioxide-CO2, Salt-NaCl, Oxygen gas-O2
Biomolecules
Monomers
 Single molecules that can be joined together to form a larger
more complex molecule
 Ex: monosaccharides, amino
acids, nucleotides
Polymers
 Compound made up of several monomers
 Ex: poly-saccharides,
lipids, proteins, DNA
Carbohydrates
 Consist of elements C, H, & O ONLY
 Examples: Sugars & starches
 Main energy source for all living things
 Plants use carbohydrates (cellulose) for structure
Monosaccharides
 Made of a single sugar molecule like glucose &
Disaccharides
 Made of two sugar molecules like lactose &
fructose
 Monomer of other complex carbohydrates
sucrose
Polysaccharides
 Made of many sugar molecules
Lipids
 Consist of elements C, H, O & sometimes P
 Types – fatty acids, triglycerides, phospholipids, & sterols
Fatty Acid
Tryglyceride
like starch or cellulose (what
plant cell walls are made of)
 Polymers
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Examples: Fats, oils & waxes
Can also be used to store energy
NOT water soluble
Cell membranes are made of phospholipids
 Vitamins, enzymes & hormones are also lipids
Vitamin A (retinol)
Proteins
Nucleic
Acids
 Consist of elements C, H, O, & N
 Polymer chain of amino acids
 Different combinations of amino
acids form different proteins
 Each protein has a specific job in an
organism such as:
o Regulating cell processes
o Transporting substances into or
out of cells
o Forming bones, muscles & other
tissues
o Fighting diseases
 Have complex folded structures
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Consist of elements C, H, O, N, & S
Store & transmit genetic or hereditary information
Polymers of individual molecules called nucleotides
Two kinds of nucleic acids: DNA and RNA
Order of the individual nucleotides in a DNA or RNA molecules
determines the traits in an organism
Parts of a Microscope
A few of the Organisms found in both plant and animal cells