This document provides an introduction to cell structure and function. It defines what cells are and how they were first discovered using microscopes in the 17th century. The three main points of the cell theory are outlined. Cell diversity is discussed in terms of size, shape, and internal organization. The main organelles of animal and plant cells are defined, including their locations and functions. The key differences between plant and animal cells are that plant cells contain cell walls, vacuoles, and plastids.

1. Introduction to Cell Notes

2. ‘
• What is one thing these to things have
in common?
• They both consist of cells.

3. Discovery of The Cell
• Every living thing from the tiniest
bacterium to the largest whale is made up
of one or more cells.

4. Discovery of The Cell
• What was developed, that allowed us to
discover cells?
• Microscopes, which was developed in the
seventeenth century.

5. Discovery of Cell
• In 1665 and English scientist Robert
Hooke used a microscope to look at a slice
of cork.

6. Disc. Cell
• These little boxes
reminded him of
small rooms which
monks lived in, and
he called them……
• Cells

7. Cell Theory
• After 150 years scientist used Hooke’s
observations to form the Cell Theory.
• The Cell Theory has 3 parts:
• 1. All living things are composed of one or
more cells.
• 2. Cells are the basic units of structure and
function in an organism.
• 3. New cells have to come from existing
cells

8. Cell Diversity
• Not all cells are alike. They are diverse in
size, shape and internal organization.

10. Cell Diversity
• 1. Size:
• Most cells only visible with a
microscope.
• A cell must have a high surface area to
volume ratio.
• Why?
• So that nutrients can enter the cell
efficiently.

11. Examples
• Largest: nerve cell in
giraffe leg is 2m
long (6.5 feet)

12. Example
• Smallest: bacteria is
0.2 micrometers
(0.000008 inches)

13. Cell Diversity
• 2. Shape: Shape of
cell reflects the cells
function (job).
• Nerve cells have long
extensions to receive
nerve signals.

14. Dead skin cells are flat to cover the
body surface

15. • White blood cells
can change shape
to move through
narrow openings
to find and destroy
bacteria

16. Cell Organization
• 3. Internal Organization:
• Organelle – “tiny organ” within cell, they
carry out specific functions for the cell to
live.
• Example:
– Nucleus – contains DNA and RNA, directs
activities of the cell

18. Types of Cells
• There are 2 types of cells:
• Eukaryotic Cells – have membrane-bound
organelles and a nucleus. ex. Animal cells
• Prokaryotic – no membrane-bound
organelles or a nucleus. ex. bacteria

20. Animal Cell Plant Cell

21. Cell Organelles
•READ THE MESSAGE
BELOW!!!!!
• You should already know all of the cell
organelles and their functions, but just in case
you forgot, the following slides will give you
the name and function of the cell organelles
that you need to know.

22. Cell Organelle
• Cell Membrane –
surrounds the cell,
made up of
phospholipids and
proteins.

23. Cell Membrane
• Function: is to control what goes in and
out of the cell.
• This means cell membranes are selectively
permeable.

24. Organelles
• Cytoplasm – the
fluid in the cell that
holds the organelles
in place.

25. Mitochondria
• Mitochondria are scattered throughout the
cytoplasm.
• Function: makes energy (ATP)
• The more ATP a cell needs the more
mitochondria it will have in the
cytoplasm.
– Ex. Liver cells and muscle cells

26. Ribosomes
• Ribosomes are the most numerous
organelles in the cell.
• Function: produce proteins.
• Some ribosomes are inserted into
membrane of endoplasmic reticulum
(called Rough E.R.)

27. Endoplasmic Reticulum (ER)
• The ER functions as
an intracellular
highway, is a path
along which
molecules move from
one part of the cell to
another.

28. Endoplasmic Reticulum (ER)
• A cell has 2 types of ER:
• Rough Endoplasmic Reticulum (rough
ER): which produces large amounts of
proteins to be exported.
– Has ribosome in membrane (makes it rough)
• Smooth ER: is used to synthesis steroids in
gland cells, regulate calcium in muscles,
and break down toxins in liver cells.

29. Golgi Apparatus
• Golgi Apparatus
Function: processes,
packages, and secrets
proteins in the cell to
prepare them for
export.

30. Lysosomes
• Lysosomes Function: are spherical
organelles that digest proteins, carbs,
lipids, DNA, RNA, organelles, and
viruses.
• Lysosomes are like the clean up crew for
the cell. (Garbage men).

31. Cilia and Flagella
• Cilia (hair like)
• Flagella (tail like)
• Function: organelles
that extend from the
surface of the cell,
where they assist in
movement.

32. Cilia and Flagella
• Cilia are also found on the surfaces of cells
in multicellular organisms.
• Where can they be found on human cell
surfaces?
• On cells lining your respiratory tract
• They trap particles from the air you
inhale.

34. Nucleus
• Nucleus function:
• 1. Stores hereditary
information in its
DNA.
• 2. Site where RNA is
copied from DNA
• 3. Contains the
nucleolus

35. Nucleus
• Most nucleus contain
one spherical area
inside the nucleus
called the Nucleolus.
• Nucleolus – is where
you find all of the
DNA.

36. Plant Cells
• Plant cell have 3 additional parts.
• 1. Cell walls
• 2. Vacuoles
• 3. Plastids
• All are important to plant functions.

37. Cell Walls
• Cell Wall - lies
outside the cell
membrane.
• The cell wall function:
helps support and
protects the cell.
• The cell wall is mostly
made up of cellulose,
a type of
carbohydrate.

39. Vacuoles
• Vacuoles function – is
a store molecules like
enzymes, wastes, and
mostly water.
• Can take up to 90% of
the cells space.

40. Plastids
• Plastids – contain pigments, which absorb
visible light (for photosynthesis).
• Most familiar type of plastid is the
chloroplast.
• Chloroplast – are organelles that convert
light energy into chemical energy
(glucose).