Organelles

1. CELL STRUCTURES

2. CELL STRUCTURES
Cell theory:
1) All living things are
made of one or more
cells
2) The cell is the basic
organizational unit of
life
3) All cells come from
pre-existing cells

3. CELL STRUCTURES

4. CELL STRUCTURES
Cell analogy: Animal cell

5. CELL STRUCTURES
Cell analogy: Plant cell

6. CELL STRUCTURES
Organelles – internal structures performing specialized
functions (not in bacteria)
All organelles have a membrane except for ribosomes and centrioles.

7. CELL STRUCTURES
Nucleus: protects and controls access to DNA, makes
ribosomes
DNA (deoxyribonucleic
acid): substance that
carries coded
instructions for cell
activity

8. CELL STRUCTURES
DNA structures:
Chromatin – combination of
DNA and protein in nucleus
Chromosomes – single piece
of condensed (coiled) DNA
with protein and RNA
Note: Some of the
chromosomes look
condensed in this diagram,
while others don’t.

9. CELL STRUCTURES
Endoplasmic reticulum (ER): routes and modifies new
proteins, & metabolizes lipids and carbohydrates
Rough ER (RER)– studded
with ribosomes for protein
synthesis
Smooth ER (SER)– no
ribosomes; performs lipid
metabolism, carbohydrate
metabolism, and
detoxification

10. CELL STRUCTURES
Golgi apparatus/body: packages proteins and lipids before
they are sent to their destination; creates lysosomes

11. CELL STRUCTURES
1. Nuclear membrane
2. Nuclear pore
3. Rough endoplasmic reticulum
4. Smooth endoplasmic reticulum
5. Ribosome attached to RER
6. Packaged materials (i.e. proteins)
7. Transport vesicles
8. Golgi apparatus
Summary:

12. CELL STRUCTURES
Vesicles: Membrane-bound containers inside a cell (4 kinds)
1) Transport/secretory vesicles –
transports substances within a
cell, or releases them from the
cell
2) Peroxisomes – contain enzymes
to break down lipids and amino
acids; inactivates toxins
3) Lysosomes – contains digestive
enzymes; digest excess or worn-
out organelles, food particles, and
engulf viruses and bacteria
4) Vacuole – contain waste products
(“garbage cans”), water, enzymes
and/or other small molecules,
export unwanted substances

13. CELL STRUCTURES
Secretory/Transport Vesicle – Can release important
molecules in the body (i.e. proteins, hormones, etc.)

14. CELL STRUCTURES
Mitochondrion: Generates ATP and other molecules
-The inner membranes
contain enzymes & channel
proteins for respiration
-Have their own RNA

15. CELL STRUCTURES
Ribosome: translates messenger RNA (mRNA) to
polypeptide chains used to form proteins
Made of two subunits which
sandwich mRNA in between

16. CELL STRUCTURES
Cytoskeleton: Dynamic system of filaments and
microtubules
Functions:
-Provides cell structure
-Helps with cell division
-Enables cell and organelles
to move around

17. CELL STRUCTURES
Centriole: Organizes the spindle fibres during cell division

18. CELL STRUCTURES
Cilia & Flagella: Used for locomotion; rotates around in a
whip-like fashion. Made of microtubules.
Cilia – smaller, more
numerous, and can move
fluids around stationary cells
Flagella – larger, less
abundant

19. CELL STRUCTURES
Cytoplasm: Includes the cytosol, organelles, and chemicals
(i.e. sugar and water); all contained by the cell membrane
Cytosol: the fluid between
the cell membrane and
nucleus

20. CELL STRUCTURES
Outside cell
Inside cell
Hence the cell membrane is called the phospholipid bilayer.
Cell membrane: A bilayer of phospholipids which contains
the contents of the cell

21. CELL STRUCTURES
This bilayer is not static; it is dynamic. There is fluidity in
the membrane.

22. PLANT CELLS

23. PLANT CELLS
Plant cells have additional organelles and features that are
not found in animal cells.

24. PLANT CELLS
Cell wall: Tough, flexible, and rigid layer around plant,
bacteria, fungi, and algae cells. Surrounds cell membrane.
-Prevents overexpansion
when water enters cell
-Protects cells against
mechanical stress
-Made primarily of cellulose

25. PLANT CELLS
Chloroplasts – Make sugars using light energy, CO2, and H2O;
contain the pigment chlorophyll for photosynthesis

26. PLANT VS ANIMAL CELLS