AG BIO - McKee

Structures & Functions

The Cell

What is “Cell Theory”? The idea that all living things are made up

of cells.

What’s so special about cells?

Cells are the smallest working units of all living things.

Yeast Cells

Where do cells come from?

All cells come from preexisting cells through cell division.

Bean Cells in Mitosis

Definition of the Cell

A cell is the smallest unit that is capable of performing life functions.

Would you like to see some examples?

Even if you don’t, too bad.

Remember… These are

magnified images taken with microscopes

Some cells have been stained with color so you can see them better.

Nerve Cell

Bacteria Cell

Tree cells from the stomach of a possum.

Brain Cell

Cornstalk Cells

Mammalian Tissue

•Smooth muscle are structurally the simplest muscle cells

•Provide contractile forces for most internal organs

•Controls flow of blood through vessels and moves food through digestive tract.

Two Types of Cells Prokaryotic Eukaryotic

Prokaryotic One-celled

organisms

Example: Bacteria

Few internal structures surrounded by membranes

Cells Dividing: Bacteria from a Taxi Cab

Eukaryotic Contain organelles surrounded by membranes Most living organisms

Plant Humans & Animals

“Typical” Animal Cell

“Typical” Plant Cell

Cell Parts and Functions

Cell WallPlant, not animal cellsOuter layer, rigid, strong, stiffMade of cellulose

Cell Parts and Functions

Cell MembranePlant & animal cellsProtects the cellLets things in and out of the

cellLocation: around the cell

Nucleus Plant & animal

cells Large & oval Control center Location:

Inside the cell, Near the center

Cell Parts and Functions

Cell Parts and FunctionsNucleolus (Nucleoli)Plant & animal cellsMakes ribosomesLocation: inside the nucleus (dark spot)

Nuclear MembranePlant & animal cellsProtects around nucleusLets things in/out of nucleus (pores)Selectively permeable cell

Cell Parts and Functions

Cytoplasm Plant & Animal Clear, thick, jellylike Holds all organelles in cell Location: in cell

Cell Parts and Functions

Chromatin/Chromosomes In Plant & Animal Cells Contains genetic

information/traits Location: In nucleus

Cell Parts and Functions

Endoplasmic Reticulum (E.R.) Plant & animal cells Network of tubes and membranes Transports materials and sends messages to all

parts of the cell Two types: smooth and rough (has ribosomes) Location: attaches from cell membrane to nuclear

membrane

Rough E.R.

Cell Parts and Functions

Ribosome Plant & Animal Cells Makes proteins Small circular shape Location:

In Cytoplasm or Attached to E.R.

Mitochondria Plant & animal Bean shaped with inner membranes Makes energy/powerhouse Breaks down sugar into energy Location: In Cytoplasm

Mitochondria

Cell Structure & FunctionVacuolePlant = few/largeAnimal = smallFluid filled sacsStores food, water &

wasteLocation: In cytoplasm

Vacuole

What does a vacuole remind you of?

Golgi Bodies or Golgi Apparatus

Located in Plant & Animal Cells Packages and secretes Gets rid of waste Location: in cytoplasm

What does a Golgi Body remind you of?

GOLGI APPARATUS

Cell Parts and FunctionsLysosomePlant & Animal CellsContains digestive enzymesDestroys bacteria, old cell parts…Location: in cytoplasm

CentriolesPlant & Animal CellsHelps the cell to divideLocation: in cytoplasm

Cell Parts and Functions

CiliaMost Plant, Animal & Bacteria CellsShort hair-like projections Used for movementLocation: outside of cell

FlagellaMost Plant, Animal & Bacteria CellsLong whip-like tailUsed for movementLocation: outside of cell

What’s that?

?

Cell Structures and Functions

ChloroplastOnly in plant cellsContains chlorophyllMakes plants greenTraps light energy from the sunLight Energy = Chemical Energy(Where photosynthesis occurs)Chemical Energy = Food for the Plant

Cell Structures and Functions

Plastids Found in Plant Cells Stores extra food Located in cytoplasm

Can you name these plant cell parts?

A.

B.

C.

Cell Parts and Functions

CytoskeletonAlso called

MicrofilamentPlant & Animal CellsMade of thin hallow

tubesLike a spider webSupports & transports“Super Highway”

Microfilament (cytoskeleton) of mouse embryo fibroblasts, stained with FITC-phalloidin (100-fold magnification.)

Can you name these animal cell parts?

Cell Membrane

Rough E.R.

Ribosome's

Cytoskeleton or Microfilaments

Mitochondria

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