This document compares and contrasts plant and animal cells. It notes that plant cells contain a tonoplast membrane surrounding the large central vacuole, while animal cells do not have this structure. Chloroplasts, the sites of photosynthesis, are enclosed by two membranes and contain thylakoids where the light-dependent reactions occur. Muscle cells are striated due to alternating dark and light bands visible under microscopy. Sperm cells have a tail that aids motility to swim towards the female egg. Protozoa are one-celled organisms that can cause diseases like malaria, sleeping sickness, and meningitis.

1. Eukaryotic cell
Lecture 3 DR./ Ahmed Hassan

2. Comparison between Plant & animal cells

4. A tonoplast is actually the membrane that surrounds the large vacuole
in a mature plant cell.
plant cell

5. animal cell

6. Questions:
1. State two differences between animal and plant cells.
2. What is the function of the cell membrane?
3. Which three features do animal and plant cells share?
4. When plant and animal cells are placed in water, most
animal cells will burst, whereas plant cells will not.
Explain this difference.
5. Where does photosynthesis take place in a plant cell?

7. Chloroplast in plant cells

8. TEM of Chloroplast

9. Chloroplasts are enclosed by 2 membranes.
 Thylakoids are membrane-bound compartments
inside chloroplasts.
They are the site of the light-dependent reactions of
photosynthesis.

10.  Thylakoids consist of a thylakoid membrane
surrounding a thylakoid lumen.
 Thylakoids frequently form stacks of disks referred to
as grana (singular: granum).
 Grana are connected by stromal lamellae.
 The space between inner membrane and thylakoid
membrane is filled with stroma
 Stroma, a matrix with enzymes, starch granules, and
nucleoid (chloroplast genome).

13. The photosynthetic machinery
 The thylakoid membrane houses chlorophylls and
different protein complexes, including photosystem
I (P700), photosystem II (P680), and ATP
synthase, which are specialized for light-
dependent photosynthesis.
When sunlight strikes the thylakoids, the light energy
excites chlorophyll pigments, causing them to give up
electrons.
 The electrons then enter the electron transport
chain, a series of reactions that ultimately drives the
phosphorylation of adenosine diphosphate (ADP) to
the energy-rich storage compounds such as ATP and

17. TEM of plant cell

18. SEM of Root hairs

19. Variety of Eukaryotic cells

21. Animal cells

22. Why are muscles called striated?
Skeletal muscle is also called striated muscle because when it is
viewed under a polarized lighter stained with an indicator, you can
see alternating stripes of light and dark.
Where are striated muscles found?
There are two types of striated muscle: Cardiac muscle (heart
muscle) Skeletal muscle (muscle attached to the skeleton)
Striated Unstriated Cardiac
These muscles are present in
body structures like hands,
legs and tongue.
They are present on the
linings of the alimentary
canal and the blood vessels.
These muscles are present on
the walls of the heart.
What are striated and Unstriated muscles?

23. In heart Attached to skeleton
In alimentary canal
wall, blood vessels,

25. TEM of Skeletal muscle cells

26. Blood cells
Thrombocytes =

27. Red and white blood cells

28. SEM of erythrocytes
TEM of intestinal cell
(enterocyte)

29. A mature human sperm cell is composed of:
1- Head: It is spherical consisting of large nucleus and a
dome shaped acrosome. Function: it contain the genetic
material. The acrosome releases a hyaluronidase enzyme
which destroys hyaluronic acid of the ovum and enters
into the ovum.
2- Neck: It contains centrioles which gives rise to axial
filament (flagellum) of the sperm.
3- Middle piece: It is tubular structure in which
mitochondria are spirally arranged.
Function: It gives energy to the sperm to swim in the
female genital tract.
Sperm cell

30. 4- Tail: It contains axial filaments. Function: Tail helps the
sperm to swim in the female genital tract (motility).

32. A- SEM of human sperms
B- SEM of human egg
1- Sex cells

33. SEM of human egg surrounded by many sperms

34. SEM of tracheal cells with mucous particles (red)

35. Neurons

36. Questions:
1. Why do sperm cells have a tail?
2. Root hair cells in plants have a large surface area. How
does this help?
3. Cells in the trachea (windpipe) have cilia hairs. What is
their job?
4. Can you suggest why red blood cells are pale in the
middle?
5. Why must the ovum be larger than the sperm cell?

37. Examples of One-celled organisms (Protozoa):
1- Trypanosoma brucei; swims in human blood plasma
and causes African sleeping sickness.
2- Naegleria and Acanthamoeba species are amoebae
live in soil and water cause PAM “Primary amoebic
meningoencephalitis” and GAE (granulomatous amoebic
encephalitis), respectively.
3- Plasmodium species live inside red blood cells and
cause malaria.
4- Paramecium is free living and has macronucleus and
micronucleus and thousands of cilia for motility.

38. Trypanosoma brucei among red blood cells

39. SEM Naegleria species

40. SEM of Acanthamoeba

41. LM of Paramecium

42. EM of Paramecium