Download Cells and Cell Theory - Pregitzersninjascienceclasses

CELLS AND CELL THEORY
Biology
CELLS
All living things are made of cells.
 A cell is the basic unit of structure that carries
out function in living things.


They form the parts of an organism and helps the
organism to function.
DISCOVERING CELLS
The invention of the microscope made it possible
to first see cells.
 Two scientists first observed cells in the 1660’s.

Robert Hooke called them cells, meaning “small
rooms”.
 Anton van Leeuwenhoek built microscopes and
looked at things with them all the time. He found
one-celled organisms.

CELL THEORY
The cell theory is a widely accepted explanation
of the relationship between cells and living
things.
 1. All livings things are composed of cells.
 2. Cells are the basic units of structure and
function in living things.
 3. New cells are produced from existing cells.

CELL STRUCTURE
There are tiny structures inside cells, called
organelles.
 Organelles carry out specific functions within the
cell.

GETTING INTO THE CELL

Cell Wall- The cell wall is a rigid
layer that surrounds plant cells.


Function- to provide support and
protection for the cell.
Cell Membrane- All cells have cell
membranes.

Function- Regulates what enters and
leaves the cell and also provides
protection and support.
THE NUCLEUS
Nucleus- “Control Center”
of the cell, which contains
DNA.
 Nuclear Envelope- A
double membrane that
surrounds the nucleus.
 Nucleolus- A small, dense
region inside the nucleus
where the assembly of
ribosomes begins.

ORGANELLES IN THE CYTOPLASM
Cytoplasm- “Jelly-like” portion of
the cell outside the nucleus. It
cushions the organelles and
provides a medium for things
inside the cell to move through.
 Mitochondria- “Powerhouse” of the
cell. They convert the chemical
energy stored in food into ATP
(molecules that cells use for
energy).

MORE ORGANELLES IN THE CYTOPLASM
Endoplasmic Reticulum- “Conveyor Belt” where
proteins and other materials are assembled and
exported from the cell.
 Ribosomes- Found throughout the cytoplasm,
these small organelles make proteins!

MORE ORGANELLES IN THE CYTOPLASM


Golgi Bodies/Apparatus“Packagers” that modify, sort,
and package proteins and other
materials.
Chloroplasts- Found mostly in
plants, they capture the energy
from sunlight and convert it into
sugar during photosynthesis.
EVEN MORE ORGANELLES IN THE
CYTOPLASM!


Vacuoles- “Storage” for water, salts,
proteins, and carbohydrates.
Lysosomes- “Garbage Disposal” that
digests “junk” that would otherwise
clutter up the cell.
HOLY COW! THERE’S A LOT OF
ORGANELLES!


Cytoskeleton- “Scaffolding”
that helps support the cell.
Centrioles- Found only in
animal cells and used
during cell division.
ANIMAL CELL DIAGRAM
PLANT CELL DIAGRAM
SPECIALIZED CELLS
There are many types of cells within your body,
each has a specific function.
 Ex: Brain cells, nerve cells, red blood cells,
immune cells, etc.

In multi-cellular (more than one cell) organisms,
cells are organized into tissues, organs, and
organ systems.
 Nerve Cells Nervous tissue  Brain 
Nervous System

BACTERIAL CELLS
Have cell walls and cell membranes.
 Contain cytoplasm and ribosomes.
 Bacterial cells do not have a nucleus or any other
organelles!

REVIEW QUESTIONS



1. What are the main ideas of the cell theory?
2. Identify two structures found in plant cells
that are not found in animal cells.
3. In what types of cells would you expect to find
a lot of mitochondria? Why?
VIDEOS
https://www.youtube.com/watch?v=BB5rvjZzgFU
 https://www.youtube.com/watch?v=dmCjuKtDi-4
 https://www.youtube.com/watch?v=yKW4F0NuUY
