Bellringer 10/8

•How are living things different from non-living things?

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Bellringer 10/9

• Without using your notes, name as many levels of organization as you can from smallest to largest.

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ALL LIFE PROCESSES ARE CARRIED OUT BY CELLS WHETHER THE

ORGANISM HAS ONLY ONE CELL OR MANY CELLS.

UNIT 2 PART 1: THE CELL

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THE CELL THEORY

• All organisms are made of one or more cells and the products of those cells.

• All cells carry on life activities.

• New cells only come from other living cells by the process of cell division.

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Organization

Organisms can have only one cell (unicellular) or many cells (multicellular).

In multicellular organisms the cells are specialized and can not live on their own.

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Organization2

Each cell carries out only some of the necessary life functions and depends on all the other types of cells.

This requires organization and energy.

ORGANIZATION

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• Biosphere• Ecosystem• Community• Population• Organism• Organ systems• Organs• Tissues• Cells• Molecules• Atoms

Levels of Organization

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Parts of a Cell:

• CELL (PLASMA) MEMBRANE• NUCLEAR MEMBRANE• NUCLEUS• NUCLEOLUS• CYTOPLASM• ENDOPLASMIC RETICULUM• RIBOSOME• GOLGI BODY• VACUOLE• MITOCHONDRIA• MICROTUBULES• MICROFILAMENTS• CILIA AND FLAGELLA

THESE ARE ONLY IN ANIMAL CELLS:

- LYSOSOME- CENTRIOLES

THESE ARE ONLY IN PLANT CELLS AND SOME BACTERIA:

- PLASTIDS (CHLOROPLAST)- CELL WALL

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Plasma (cell) Membrane• The plasma membrane

separates the cell from its environment.

• It regulates movement of materials in and out of the cell.

• Maintains homeostasis• Homeostasis –

maintaining a constant internal environment.

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• A fluid-mosaic of phospholipids and proteins.

• Phospholipids form a thin, double layer that is a barrier to many other molecules.

Cell Membrane Structure

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• Proteins float within the lipid bilayer & perform a variety of jobs:a.Transport channelsb.Enzymesc.Receptorsd.Identity markerse.Adhesivesf.Cytoskeleton

Bellringer 10/15

• Predict what would happen over time if I sprayed perfume in one corner of the room.

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Diffusion• The movement of

molecules from a region of high concentration to a region of low.

• The difference between the high and low concentrations is called the concentration gradient.

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• Diffusion is a type of passive transport: it does not cost the cell any energy.– Ex: perfume

• Some molecules get help across: facilitated diffusion

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Osmosis• Osmosis is the diffusion of water across a membrane

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Active Transport

• Active transport uses energy (ATP) to move molecules against the concentration gradient from low to high

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Nucleus & Nucleolus

• The nucleus is surrounded by a nuclear membrane.

• The nucleus controls all activities of the cell.

• The nucleus contains chromosomes that are made of DNA.

• The nucleolus makes RNA and ribosomes needed for protein synthesis.

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Nuclear Membrane• The nucleus is encased by a double membrane.• The nuclear membrane is full of pores that let

RNA and ribosomes pass through it.• The membrane forms the ER, lysosomes &

golgi body.

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Cytoplasm• The jellylike stuff inside

the cell

• It acts as a solvent

• Many biochemical reactions take place here

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Bellringer 10/19

• What is the difference between active transport and passive transport?

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Endoplasmic Reticulum• Membrane bound, fluid-filled canals that form a continuous

network with one extremely large enclosed space

• Manufactures, processes, and transports molecules used in and out of the cell

• Rough ER hasribosomes on it

• Smooth ER has noribosomes

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Ribosomes

• Site of protein synthesis

• Made of RNA from nucleolus

• May be on Rough ER or free in cytoplasm

• Not surrounded by a membrane

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Golgi Bodies• Form from bubbles off of

the ER (like a lava lamp)

• Bubbles join into flattened sacs, making a ‘stack of sacs’

• Synthesize, package & secrete cellular products for use in the cell or export

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Lysosomes• Formed from the Golgi body, this membrane

bound sack contains digestive enzymes, like a stomach. Food Vacuole

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Vacuole

• Membrane bound space that contains– Food– Water– Waste

• Contractile vacuole pumps water out of the cell

V

V

CV

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Mitochondria• Site of aerobic

cellular respiration– Provides energy for

the cell to use– Converts energy

stored in food to ATP

• Double membrane bound organelle– Outer smooth– Inner folded

• Bacteria-like structure

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MICROTUBULES AND MICROFILAMENTS

• MICROTUBULES – Long, hollow cylindrical

structures– Cell skeleton– Found in centrioles, cilia,

flagella

• MICROFILAMENTS– Threadlike strands– Cytoplasmic streaming

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Centrioles

• Two found in animal cell cytoplasm near the nucleus

• Function in cell division

• Make spindle fibers• Cylinder of 9 triplets

of microtubules

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Cilia & Flagella

• Used in locomotion & feeding– Flagella: 1 long

whip– Cilia: Many

small hairs

• Similar in structure to centrioles

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Chloroplast• Site of photosynthesis

– Captures light energy– Makes food (sugar)

• Double membrane bound organelle similar to mitochondria– Inner membranes are

arranged into stacks called grana

– Grana contain Chlorophyll

• Bacteria-like structure

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CELL WALL

• FOUND ONLY IN PLANTS AND BACTERIA

• FOR SUPPORT AND PROTECTION

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