Presentation on cell, structure and functions

2. -structural and functional unit of organisms
- Organisms function as one-celled (unicellular)
and others perform task as many-celled
(multicellular) organisms.
CELL THEORY
-states that cell is the unit of structure and
function of all living things and all living cells
come from pre-existing cells.

3.  1665 – Robert Hooke examined a thin slice of
cork under a microscope
 1674 – Anton van Leeuwenhoek observed
RBC, sperm cells, and a multitude of single-
celled organisms.
 1831 – Robert Brown discovered the nucleus
 Brownian movement (1827)

4.  1838 – Matthias Schleiden stated that all
plants are composed of cells.
 1839 – Theodor Schwann concluded that all
animals are composed of cells.
 1858 – Rudolph Virchow theorized that all
living cells come from preexisting living
cells.

5. 1. All living things are made of cells.
2. Cells are the basic units of structure and
function in all living things. In other words,
cells are like the building blocks of all living
things.
3. New cells are only made from existing cells.

6.  Cells without a true nucleus
 Characteristic of bacteria with a size ranging
from 1 to 10 micrometer
 Outer boundary is composed of cell wall and
plasma membrane
 Cytoplasm contains ribosomes, thylakoids
and innumerable enzymes
 Nucleoid contains single chromosome (DNA
only)

7.  Cells with true nucleus
 Characteristics of protists , fungi, plants and
animals
 Consists of a plasma membrane, cytoplasm and a
distinct nucleus
 Outer membrane is composed of plasma
membrane made up of phospholipid bilayer with
embedded proteins
 Nucleus is membrane-bound containing multiple
chromatin
 Cytoplasm contains compartmentalized
organelles

9. 1. Plasma Membrane
- molecular bilayer of phospholipid with the
proteins arranged at random outer half, inner
half o the lipid, or extend entirely through the
bilayer.
- Fluid-mosaic model by Singer and Nicholson
(1972)
- Gives strength, shape, and protection to the
cell

10.  Substance that exhibits the properties and
activities of life
 The living material of the cell
a. Cytoplasm
- Cell content outside the nucleus
- Most active region of the cell due to numerous
biochemical reactions of the organelles
b. Karyoplasm
- Protoplasm inside the nucleus

11.  Permanent sub-cellular structures performing
metabolic functions
Nucleus
-most distinct organelle usually situated at the
center of the cell, bounded by a double
membrane
-controls and regulates the functions of other
organelles
- Contains nucleoplasm, nucleolus, and
chromatin materials

12. -forms the cytoplasmic skeleton composed of
complex system of membranes
-serves as routes for the transport of materials
between various parts of the cytoplasm
- Rough ER: with ribosome, smooth ER: without
ribosome
Ribosomes
-spherical bodies that may be attached to the
ER or free in the cytoplasm
-serve as site of protein synthesis in the cell

13. -membrane-bound vesicles of flattened sacs
and stacks parallel to each other
-serve as storage modifications and packaging
of secretory products in vesicles
Mitochondria
-double-membrane organelles, smooth outer
membrane and folded inner membrane (cristae)
-site of cellular aerobic respiration (Kreb cycle)

14. -membrane-enclosed bodies containing
numerous enzymes
-contains hydrolases, which catalyse the
digestion of proteins, nucleic acids, some
carbohydrates and fats
Vacuoles
- fluid-filled cavities surrounded by
membranes
- Regulates the molecular traffic between
the vacuole and cell substances

15. -composed of microtubules located in the
centrosome outside the nucleus
-associated with the formation and
anchoring of the spindle fibers during cell
division of animal cell
Cilia and flagella
-structures used for locomotion of the cell
-consists of microtubules arising from the
basal body

16. Chloroplasts
-double-membrane organelles found only in
plant cells
-site of food production (photosynthesis)