It tackles the different parts of cells and includes the cell cycle

1. General Attributes of the
Cell
Servano, Marlyne
Cajipo, Ma. Jobelle

2. Discovery of Cells
• ROBERT HOOKE
• First discovered cells in 1665.
• Observed a piece of bottle cork
under a compound microscope and
noticed miniscule structures that
reminded him of small rooms.
• He gave them their name because
the cella (Latin for small rooms).
Figure 1. Hooke
sketched these cork
cells as they
appeared under a
simple light
microscope.

3. Important Cell Structures or Organelles

4. 1. Nucleus
• Thought as cell’s headquarters
• Contains the majority of the cell’s DNA.
• Sends out messages to tell the cell to grow, divide or die.
• Separated from the rest of the cell by a membrane called the
nuclear envelope.

5. 2. Plasma Membrane
• Is predominantly made up of phospholipids which
prevent water-based substances from entering the
cell.
• Contains a range of receptors, which carry out a
number of tasks including:
• Gatekeepers
• Markers
• Communicators
• Fasteners

6. 3. Cytoplasm
• Is the interior of the cell that surrounds the
nucleus and is around 80% water.
• It includes the organelles and a jelly-like fluid
called cytosol.

7. 4. Lysosomes and Peroxisomes
• Are essentially bag of enzymes
• Lysosomes contain enzymes that break down large
molecules, including old parts of the cells and foreign
materials.
• Peroxisomes contain enzymes that destroy toxic
materials, including peroxide.

8. 5. Cytoskeleton
• Considered the scaffolding of the cell.
• It helps it maintain the correct shape.
• Plays a role in cell division and cell motility.
• Helps the cell signaling through its involvement in the
uptake of material from the outside of the cell
(endocytosis).

9. 6. Endoplasmic Reticulum
• Processes molecules within the cell and helps transport
from their final destination
• Made up of elongated sacs called cisternae held together
by the cytoskeleton.
• Two types:
1. Rough endoplasmic reticulum
2. Smooth endoplasmic reticulum

10. 7. Golgi Apparatus
• Sometimes considered the post office of the cell,
where items are packaged and labeled.

11. 8. Mitochondria
• Powerhouse of the cell
• Help turn energy from the food that we eat into energy
that the cell can use adenosine triphosphate (ATP).

12. 9. Ribosomes
• Read the RNA and translate into protein by sticking
together amino acids in the order defined by the RNA.

13. Cell Reproduction
• The process by which cells reproduce by dividing into
two.
• Each dividing cell is called mother/parent cell; and its
descendants are called daughter cells.
• The parent cells transmit copues of its hereditary
information (DNA) to its daughter cells, which represent
the next cell generation.

14. The Cell Cycle
• Is a series of events that cells go through as they grow
and divide.
• Begins when the cell grows, then prepares for division
and divides to form two daughter cells.
• It is divided into three phases:
1. Interphase
2. Mitotic Phase
3. Cytokinesis

15. 1. Interphase
• Cell grows into its mature size, makes a copy of its DNA and prepares for
division.
• During interphase is made up of 3 separate parts:
1. G1 Phase – a period of activity which cells do most of their growing.
2. S Phase – when the chromosomes are replicated and the synthesis of DA
occurs. Other proteins associated with the chromosomes are likewise
synthesized during this phase.
3. G2 Phase – shortest of the three phases of interphase. Organelles and
molecules required for all cell division are produced. When G2 is
completed, the cell is ready to enter the mitotic phase and begin the
process of cell division.

17. 2. Mitotic Phase
• The division of the cell
nucleus is divided into four
stages:
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase

18. 3. Cytokinesis
• The division of the cytoplasm takes place during
this phase.

19. Mitosis
- Comes from the Greek word, mitos, meaning “thread”
describing the threadlike chromosomes that appears in
the cell before it divides into two.
- Occurs in somatic or body cells.

20. 1. Prophase
• The chromatin condenses into chromosomes.
• Each consists of two sister chromatid held together at a
centromere.
• The centrioles separate, and the spindle begins to form.
• The nuclear membrane breaks down and nucleolus
disappears.

21. 2. Metaphase
• The chromosomes line up at the center of the cell or at its
equator.
• The spindle fiber on the either side of chromosomes extend
to opposite poles of the spindle.
• Unattached spindle fibers reach beyond the equator and
overlap.

22. 3. Anaphase
• The sister chromatids separate into individual chromosomes
and move apart.
• As the spindle fiber attached to the chromosomes
disassemble, each poles receive a daughter of chromosomes.
• The spindle poles move apart as the unattached spindle fiber
sides past one another.
• This contributes to chromosome separation.

23. 4. Telophase
• The chromosomes gather at opposite ends of the cell and lose
their distinct shapes.
• Two new nuclear envelopes form. The chromosomes change
back to chromatin, the nucleoli reappear, and the spindle
disappears
• Each nucleus formed contain the same number and kinds of
chromosomes as the original parent cell.
• Division of the cytoplasn begins, a process called cytokinesis.
• The above stages of mitosis may last for a few minutes to
several days.

24. Meiosis
• Is where the genetic information in each new cell is halved.
• A type of cell division that occurs only on reproductive cells or
gametes.
• Occurs only in diploid cells (2n) and produces four daughter
nuclei, which in turn half as many chromosomes replicate into two
daughter nuclei.
• At the end of meiotic stages, four haploid daughter nuclei from
the present nucleus are produced.