CELLS AND CELL CELLS AND CELL THEORYTHEORY

© J Beauchemin 2006

CHARACTERISTICS OF LIVING THINGS….(A REVIEW)

are made up of cells (organization).

respond to the environment. have the ability to reproduce. move. grow and develop. perform metabolic processes.

ALL LIVING THINGS ARE MADE UP OFCELLS….

The cell is the smallest unit of a living thing.

If an organism is unicellular, all functions of life happen within that one cell.

If an organism is multicellular, different cells have different jobs and they all work together.

CELL THEORY- HOW IT CAME ABOUT

1660’s – Robert Hooke discovered the cell He looked at cork under the microscope

(30x) He noticed little compartments, which he named after the little rooms that monks lived in…”Cells”

1670’s – Anton von Leeuwenhoek described

microorganisms in pond water He looked at pond water under the microscope

(300x) He noticed that the water was full of moving

living things

CELL THEORYWith the invention of the microscope

and the contributions of many scientists, a very important question

was answered in the1850’s.

The question was:

Where do cells come from?

CELL THEORYThere are three concepts to the

cell theory…

1. Every living thing is made up of one or more cells.

2. Cells carry out the functions needed to support life.

3. Cells come only from other living cells.

CELLS AND CELLS AND ORGANELLESORGANELLES

© J Beauchemin 2006

CELL ORGANELLESOrganelle= “little

organ”

Found only inside eukaryotic cells

CELL MEMBRANE Boundary of the cell Made of a phospholipid bilayer- fatty, porous, made also of phosphorus

BAG-CELL:ziploc

NUCLEUSControl center of

the cellContains DNASurrounded by a

double membraneUsually the

easiest organelle to see under a microscope

BAG CELL: CHESNUT

ENDOPLASMIC RETICULUM A.k.a. “ER” Highway of the cell Rough ER: studded

with ribosomes; it makes proteins

Smooth ER: no ribosomes; it makes lipids (fats)

BAG CELL: RAMAN NOODLES

RIBOSOMEWhere protein is

madeFound attached

to rough ER or floating free

Produced in a part of the nucleus called the nucleolus

GOLGI APPARATUS(BODY)

Looks like a stack of plates or ribbon candy

Stores and packages proteins

Molecules transported to and from the Golgi by vesicles

BAG CELL: RIBBONCANDY

VESICLESBud off from the

Golgi bodies

Hold and then move the protein molecule

BAG CELL: ENVELOPE

LYSOSOMES Garbage

disposal (or recycling) of the cell

Contain digestive enzymes that break down wastes

BAG CELL: SKITTLES

MITOCHONDRIA“Powerhouse of

the cell”Cellular

respiration occurs here to release energy for the cell to use

BAG CELL: CASHEW NUT

CYTOPLASMGel-like material

in a cell where all the organelles are

Supports the organelles

Gives cell shape

BAG CELL: OIL OR JELLO

PLANT CELLSPLANT CELLS

© J Beauchemin 2006

CELL WALL Found in plant and

bacterial cells Rigid, protective

barrier Located outside of

the cell membrane Made of cellulose

(fiber) BAG CELL: PAPER

BAG

CHLOROPLAST Found only in plant

cells Contains the green

pigment chlorophyll

Site of food (glucose) production

BAG CELL: GREEN SKITTLES

VACUOLES Large central

vacuole usually in plant cells

Many smaller vacuoles in animal cells

Storage container for water, food, enzymes, wastes, pigments, etc

BAG CELL: WATER BALLOON

WHAT HAPPENS TO THE VACUOLE WHEN A PLANT

DOESN’T GET ENOUGH WATER?

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SIMILARITIES BETWEEN PLANT SIMILARITIES BETWEEN PLANT CELLS AND ANIMAL CELLSCELLS AND ANIMAL CELLS

Both have a cell membrane surrounding the cytoplasm

Both have a nucleus

Both contain mitochondria

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DIFFERENCES BETWEEN PLANT DIFFERENCES BETWEEN PLANT CELLS AND ANIMAL CELLSCELLS AND ANIMAL CELLS

Animal cells Plant cells

Relatively smaller in size

Irregular shape

No cell wall

Relatively larger in size

Regular shape

Cell wall present

24Animal cells Plant cells

Vacuole small or absent

Glycogen as food storage

Nucleus at the center

Large central vacuole

Starch as food storage

Nucleus near cell wall

DIFFERENCES BETWEEN PLANT CELLS DIFFERENCES BETWEEN PLANT CELLS AND ANIMAL CELLSAND ANIMAL CELLS

QUICK REVIEW Which organelle is the control center of the

cell? Nucleus

Which organelle holds the cell together?Cell membrane

Which organelles are not found in animal cells?Cell wall, central vacuole, chloroplasts

Which organelle helps plant cells make food?Chloroplasts

What does E.R. stand for?Endoplasmic reticulum