Download Cell Structure and Function

Name _
KEY____________________________
Date _________
Class ________
Cell Structure and Function
All living things are composed of cells. The cell is the basic structural unit of all
life. All organisms are made up of cells and all the substances of an organism are
products of the cell. More than three hundred years ago an English scientists by
the name of __Robert Hooke
_________ (1635-1703) observed some thin
slices of cork. In Hooke’s report, Micrographia, he described what he had seen
through his microscope. Hooke said that the cork was a mass of
“_Tiny Cavities____”. Each cavity was surrounded by walls which reminded him of
a __Bee’s Honeycomb__, so he called these structures cells.
It was not until the early 1800’s that the first specific ideas about cells were
presented. In 1831, a British botanist, _Robert Brown______, observed a cell
structure he called the _Nucleus____________. In 1831, a French biologist,
Dujardin (Doo-Zhar-Dan), was observing living cells and found the substance we
now call the protoplasm. In 1839, two German biologists, Matthias Schleiden
(Shly-den) and Theodore Schwann (Shvahn), along with the help of many other
scientists, developed what we now call the “_Cell Theory____”.
The Cell theory
1. All plants and animals are composed of cells and cell parts.________
2. All life functions are performed by individual cells or group of cells.___
3. Cells come from other cells by reproduction.______________________
Levels of Organization
Cells
Tissues
Organs
Organ Systems
Organism
Name _
KEY____________________________
Date _________
Class ________
Definition of a Cell
Smallest unit that is capable of performing LIFE functions
Two Types of Cells
Prokaryotic Cell
1. Do NOT have structures
surrounded by membranes
and do NOT contain a
Nucleus
Eukaryotic Cell
1. Structures are surrounded
by membrane and has a
nucleus
2. Many internal structures
2. Few internal structures
3. One-celled organisms
a. Ex: bacteria
3. Multi-cellular organisms
a. Ex: humans, plants,
animals
Name _
KEY____________________________
Date _________
Cell Organelles
Surrounding the Cell:
1. Cell Membrane

Outer membrane of the cell that controls
movement in and out of the cell

Double layer

Found in both plant and animal cells
2. Cell Wall

Most commonly found in plant cells
and bacterial cells

Supports, protects and gives shape to the cell
Inside the Cell:
3. Nucleus

Brain of the cell

Directs all the cell activities

Surrounded by a nuclear membrane

Contains genetic material
4. Nucleolus

Located inside the nucleus

Contains RNA to build proteins
Class ________
Name _
KEY____________________________
Date _________
5. Chromosomes

Genetic “CODE” material
6. Nuclear Membrane

Surrounds the nucleus

Opening allows material to enter
and leave the nucleus
7. Cytoplasm

Jelly-like material substance

Surrounded by cell membrane

Chemical reactions within the cell
take place here
8. Lysosomes

Garbage truck

Picks up waste and transports it
to the cell membrane for removal
9. Endoplasmic Reticulum (ER)

The “HIGHWAY”

Transports cell substances

Smooth ER: no ribosome’s

Rough ER: contains ribosome’s
Class ________
Name _
KEY____________________________
Date _________
10. Ribosome

Make proteins (RIB=Protein)

Found on the ER or within the cytoplasm

Each cell contains thousands

RIBS (meat)  Protein
11. Mitochondria

“POWERHOUSE” of the cell

Produces energy through digestion

Recycles and decomposes food of cells
12. Golgi Bodies

Stores and releases chemical in the cell

Moves materials within the cell and
Out of the cell
13. Vacuole

Water Storage

Sac for storage of water

Larger in plant cells than animal cells
14. Chloroplast

Where photosynthesis takes place
in the plant cell

Chloroplast is made up of chlorophyll
Class ________
Name _
KEY____________________________
Date _________
Class ________
Questions:
1. Describe the four ways plant cells differ from animal cells.

Plant cells contain chloroplast

Plant cells contain a cell wall

Plant cell has a larger vacuole

Shape: animal cell round, plant cell square
2. Identify the cells below as, plant or animal cell.
Animal
Plant
Name _
KEY____________________________
Date _________
Class ________
Processes of life
1. Nutrition: Cells need food for energy and use it as building materials
within the cells. Some cells produce their own food (autotrophs) while
others take food from the environment (heterotrophs).
2. Digestion: Foods must be broken down into simpler substances in order
for the cells to use them.
3. Absorption: Cells absorb water, food materials, and other materials from
the environment.
4. Biosynthesis: The process by which cells organize substances.
Biosynthesis is necessary for growth and for the production of special
substances, called enzymes that control cell activity.
5. Respiration: Chemical energy is releases when certain substances in the
cell are broken down apart. This energy is necessary for all cell
activities.
6. Excretion: The process by which wastes materials are passed from inside
the cell to the surrounding environment.
7. Secretion: When cells pass off certain substances, these substances
affect the activities of other cells.
8. Response: Cells respond to changes in their environment such as heat,
light, and pressure.
9. Reproduction: Cells split into two identical parts from time to time to
produce more cells within an organism or to produce new organisms.