12. Outer and Inner morphology of the eukaryotic cell

Question 1

Two main part of E cells?

Answer 1

• Cytoplasm

- Nucleus

Question 2

The plasma membrane?

Answer 2

The plasma membrane: composed of phospholipid bilayer w/ embedded proteins

-Primary function of PM is to protect cell from its surroundings
-Separates the cytoplasm from the extracellular environment
-Plasma membrane is partially permeable – selectively permeable to ions/organic molecules  regulates the traffic/movement of substances in/out of the cell
-The plasma membrane contains:
•Proteins called integrins
•They are linked to cytoplasmic cytoskeletal filaments & extracellular molecules
•Through these linkages there is a constant exchange of influence, in the both ways, between the extracellular matrix and the cytoplasm.
-It is the phospholipid bilayer:
•Double membrane
•Made up of phospholipids – hydrophilic (phosphate head) and hydrophobic end (two fatty acid tails)

Question 3

The cytoplasm?

Answer 3

The cytoplasm:

-The cytoplasm itself is composed of:
-> A fluid component/ or cytosol 
•Which have metabolically active structures : 
•The organelles – can be membranous (such as mitochondria)
•Eukaryotic cells are determined by components of the cytoskeleton.
->Other minor cytoplasmic structures:
•Inclusions: deposits of carbohydrates, lipids or pigments

Question 4

The cytoskeleton?

Answer 4

Network of microtubules, intermediate filaments/ microfilaments is the cellular skeleton within the cell.

Cytoskeleton :

1. Maintains the cells shape
2. Protects the cell
3. Enables some cell motion (using cilia and flagella)
4. Plays important role in intra-cellular transport
5. Is involved in cellular division

Question 5

Cilia and Flagella?

Answer 5

Cilia and flagella:
-External surface attachment
-They aid:
•Motion of cell
•Adhesion of materials 
•Movement of materials on the outside cell

-Internal structure:
•Consists of microtubules – movement occurs by the coordinated movement of the microtubules

Question 6

Ribosomes?

Answer 6

• Small structures
• Site of protein synthesis under instruction of DNA
• Can be attached to ER = RER/ floating free in the cytoplasm

Question 7

Mitochondria and Chloroplasts?

Answer 7

Mitochondria/ Chloroplasts: Both energy related organelles are believed to have evolved from prokaryotes that began living symbiotically within eukaryotic cells.

-Mitochondria 
•Powerhouses of the cell
•The final/most energy-productive steps of respiration occurs to generate ATP
-Chloroplasts
•Possessed only by plants
•Organelles containing pigment chlorophyll
•They harness sunlight  turn into  ATP energy.

Question 8

What is Symbiotically?

Answer 8

SYMBIOTICALLY:

A CLOSE, PROLONGED ASSOCIATION BETWEEN TWO OR MORE DIFFERENT ORGANISMS OF DIFFERENT SPECIES THAT MAY, BUT DOES NOT NECESSARILY, BENEFIT EACH MEMBER.

Question 9

The endomembrane system?

Answer 9

-Includes:
•	Nuclear envelope
•	Endoplasmic reticulum, 
•	Golgi apparatus,
•	Lysosomes, 
•	Vacuoles, 
•	Vesicles, 
•	Endosomes 
•	Cell membrane

These organelles transport materials in/out/ within the cell carrying out many of the functions required for the cell to survive, grow and reproduce.
-Doesn’t include:
•Mitochondria/ Chloroplasts:
•B/c they have separate DNA and were actually parasitic bacteria (at one point)
•They evolved into symbionts and are not integral (vital) to the cell