cytoplasm(author v.mazuru)

8/19/2019 Cytoplasm(Author v.mazuru)

1/46

Cytoplasm


2/46

Components

Cytosol (Hyaloplasm)

Organelles

Inclusions


3/46

Cytosol

- H20

- Macroelements (proteins, lipids, carbohydrates)

- MicroelementsFunctional states

Sol Gel


4/46

Organelles

- Suspended in the cytosol

- Provide cell’s specific functions

- Permanent- Required for the cell life


5/46

Organelles classifications

1. By the rate of spreading

2. By the structure

3. By the function


6/46

(1) By the rate of spreading

General ImportanceIn all the cells

1. Ribosomes

2. Rough Endoplasmic Reticulum

3. Smooth Endoplasmic Reticulum4. Golgi Apparatus

5. Lysosomes

6. Peroxisomes

7. Mitochondria8. Centrosome

9. Cytoskeleton

Special ImportanceOnly in some cells

1. Microvilli

2. Cilia (StereoC, KinoC)

3. Flagellum4. Tonofibrils

5. Myofibrils

6. neurofibrils


7/46

(2) By the structure

MembranousNon-membranous

1. Ribosomes

2. Centrosome

3. Cytoskeleton

The endomembraneis present

The endomembraneis absent

1. rER

2. sER

3. GA

4. L

5. P

6. M


8/46

(3) By the function

Synthetic

1. R

2. rER

3. sER

4. GA

Structural

1. CS

2. C

Digestive Energetic

1.L

2. P1.M


9/46

Ribosomes

1. Two subunits (Small 40S; Large

60S)

2. rRNA

3. Produced in nucleolar organizer4. Combined only in translation; in

resting state subunits stay apart

5. Polysomes – ribosomal complexes

6. Protein synthesis for own needs


10/46

Rough Endoplasmic Reticulum

1. Anastomozing system of cisterna

and channels

2. Continuation of the outer nuclear

membrane

3. Ribosomes inserted to the outer

face of endomembrane

4. Proteins synthesis for the export


11/46

Smooth Endoplasmic Reticulum

1. Continuation of rER

2. No Ribosomes

3. Synthesis of lipids andCarbohydrates

4. Drugs detoxification (liver,

kidneys)

5. Ca2+ starage


12/46

Golgi Apparatus


13/46

Golgi Apparatus

GA Functions

1. post-synthetic processing

of the substances

2. Sorting3. Packaging

4. Lysosomes formation


14/46

Lysosomes


15/46

Lysosomes

1. Produced by GA

2. Enzymes (acidic hydrolases)

3. Digestion of all

macromolecules types4. Protonic pumps on the

surface

Types:

a. Primaryb. Secondary (Phagosomes)

c. Tertiary (Residual bodies)


16/46

Types of digestion

1. Heterophagy -substances which entered to

the cell by endocytosis

2. Autophagy – digestion ofthe own old components

3. Crinophagy – specific forendocrine glands (maturation

of the hormones)


17/46

Peroxisomes

1. Shape - spherical

2. Origin – from ER by buding

3. Functions:

- Reduction of ROS (H2O2)CATALASE – their MARKER

- Digestion of VLCFA (Very

Long Chain Fatty Acids)

- Digestion of Purines- Synthesis of cholesterol


18/46

Mitochondria

1. Two membranes (outer is

smooth, outer forms the cristae)

2. IM Space – similar to the cytosol

except molecules >5000 daltons

3. Crista space – filled with matrix(REDOX enzymes, ATP enzymes)

4. Has its own DNA

5. Possesses ribosomes

6. High concentration of Ca2+


19/46

Cytoskeleton

1. The largest organelle2. Three components

3. Dense fibrilar meshwork

throuout all the cell

4. Functions

a. Cell shape

b. Cell moving

c. ICJ formation

d. Mitotic spindle formation

e. Cytokinesis

f. The core of microvilli, cilia,

flagella


20/46

Cytoskeleton


21/46

Centrosome

1. Two centrioles

2. Microtubules

3. Each centriole - 9 triplets

4. Each triplet – tubule A,B,C

5. Formation of mitotic

spindle


22/46

Microvilli

1. Apical elongations of Epithelial cells

2. Have a core of actin microfilaments

3. Form the “BRUSH BORDER”

4. Enhance the efficiency of absorption

5. Location – Intestine, kidneys


23/46

Cilia and Flagellum

1. Have a core of microtubules

covered by the cell membrane

2. The core is Axoneme (9x2)+2

3. At the basis – BASAL BODY (9x3)


24/46

Inclusions

1. Surrounded by endomembrane

2. Have a content

3. Transitory structures of cytoplasm

4. Are not required for cell lifeTypes:

a. Pigmental

b. Secretory

c. Excretory

d. Trophic (nutritious)


25/46

Lipid droplets Glycogen droplets


26/46

Nucleus, Cell Cycle


27/46

Nuclear components

1. Nuclear envelope

2. Nuclear pore-complexes

3. Nucleoskeleton

4. Nucleoplasm5. Chromatin (Eu and Hetero)

6. Nucleolus


28/46

Nuclear envelope

1. Double membrane with a cavity between (perinuclear cisterna)

2. Outer Nuclear Membrane continues with rER

3. Inner Nuclear Membrane is enforced by nucleoskeleton (Laminine

A,B,C)

4. Nuclear pore-complexes


29/46

Nuclear pore-complex

Transport gates Nucles/Cytoplasm

1. Three proteic rings (each ring 8

proteins)

2. Outer (cytoplasmic proteic ring)

has receptors

3. Inner (nucleoplasmic proteic

ring) has a basket with a central

granule

4. Open into the cisterna of rER


30/46

Chromatin

1. Preserves and transmit genetic

information

2. Euchromatin and

Heterochromatin

3. Content: DNA, RNA, histones,non-histones

4. Chromosomes – the highest

level of chromatin condensation


31/46

Euchromatin

1. Decondensed portions of Chromatin

2. Invisible in light microscope

3. Active (participates in transcription)


32/46

Heterochromatin

1. Condensed portions of chromatin

2. Visible in light microscopy

3. Inactive (does not participate in transcription)


33/46

Nucleolus(Nucleolar organizer)

1. The darkest part of the nucleus

2. Formed by 5 chromosomes

3. Present only in interfase

4. Number could vary

5. Consists of 2 parts: granular and

fibrous

6. Function: ribosomal subunits

formation


34/46

Cell Cycle

1. The period of cell life between two mitotic divisions

2. Consists of: Interphase and Cell Division


35/46

Interphase

Period between the divisions

1. G1 (Growth period)

2. S (Synthesis)3. G2 (preparing for a new division)


36/46

G1 Period

1. Right after cellular division

2. Intensive formation of Ribosomes

3. Proteins and enzymes syntesis

4. ATP formation

5. Daughter Cell reestablishes the Mother Cell size

CELL GROWTHS


37/46

S-Period

1. Doubles the amount of DNA (Replication)

2. Doubling of Centosome


38/46

G2-Period

1. Maturation of Centrosome

2. Their migration to the opposite poles of the cell

3. Formation of mitotic spindle

4. ATP synthesis

CELL PREPARES FOR DIVISION


39/46

Cell Division

Mitosis – somatic cells

Meiosis – sex cells

MITOSIS

Absolutely identical reestablishing of Genetic Material in

the daughter cells comparing to the Mother CELL

1. Prophase2. Metaphase

3. Anaphase

4. Telophase


40/46

Prophase

Key Events:

1. Disassembling of nuclear

envelope2. Chromatin Condensation

(Chromosome appear)

3. Disappears the Nucleolus


41/46

Metaphase

Chromosomes attach

to the tubulines of the

mitotic spindle in the

equatorial plane of thecell.

METAPHASEAL

PLATE


42/46

Anaphase

Synchronous movement of

the chromatids to the

opposite poles of the cell.

Fail of bichromatidic

chromosomes disrupting

leads to the Aneuplodia


43/46

Telophase

Key Events:

1. Reassembling of nuclear

envelope2. Chromatin deondensation

(Chromosome disappear)

3. Reappears the Nucleolus


44/46

Cells not

cyclingG1

S

G2

G0

DNA

synthesis

Mitosis

For a 24 hour cycle,

M Phase lasts about

1 hour.


45/46

Cell Death

Apoptosis

- Genetically programmed

- Cellular components

deacreases- Eventually the dead cell is

disassembled into the small

“apoptotic particles”

Necrosis

- Violent death

- Swelling of the cell

components- Destroying of lysosomes

- Itself digestion


46/46

cytoplasm(author v.mazuru)

Documents