The cell and it's organs

Question 1

Name the four functional characteristics of cells

Answer 1

1- Cell metabolism and energy use
2- Synthesis of molecules
3- Communication
4- Reproduction

Question 2

Function and structure of the plasma membrane

Answer 2

Function: Encloses and supports cellular contents. Controls what goes into and out of the cell. Intercellular communication.
Structure: Lipid layer (Phospholipids and cholesterol 50%. Carbohydrates 4-8%. Proteins 45-50%.).

Question 3

Describe the two features of the cytoplasm

Answer 3

Cytosol: Fluid portion of the cytoplasm. Cytoplasmic inclusions such as melanin
Cytoskeleton: Supports the cell and organelles. Shape of cell. Microtubules, Microfilaments and intermediate filaments are all made up of proteins.

Question 4

Function and structure of the nucleus

Answer 4

Function: DNA carries the code for the structural and continual characteristics of the cell.
Structure: Nuclear envelope covered in nuclear pores. Contains nucleolus which primarily produces ribosomes.

Question 5

Function and structure of ribosomes:

Answer 5

Function: Sites of protein synthesis
Structure: Composed of one large and one small subunit.

Question 6

Where are ribosomes found?

Answer 6

Nucleus, Nucleolus and Cytoplasm

Question 7

Structure and function of endoplasmic reticulum

Answer 7

Structure: Fattened, interconnecting sacks and tubules. Usually surround the nucleus. Smooth and rough.
Function: Smooth- Site of lipid, steroid and carbohydrate synthesis. Also detoxification.
Rough- Synthesis and modification of proteins

Question 8

Structure and function of the Golgi Apparatus

Answer 8

Structure: Flattened membranous sacks with cisternae. Secretory vesicles.
Function: Modifies, packages and distributes proteins and lipids that are made in the rough ER.

Question 9

Structure and function of lysosomes

Answer 9

Structure: Membrane bound vesicles that form at the Golgi apparatus.
Function: Digestion of molecules no longer needed by the cell. Fuses with vesicles full of unwanted molecules and destroys those molecules.

Question 10

Structure and function of the mitochondria

Answer 10

Structure: Outer membrane and inner membrane matrix. Change shape continuously. Has own genetic material to make itself.
Function: Provides ATP (energy) for the cell to function.

Question 11

Structure and function of centrioles

Answer 11

Structure: Barrel shaped organelles orientated at right angles to each other. Form the centrosome. Wall is composed of microtubules.

Question 12

Structure and function of cilia

Answer 12

Structure: Whip-like, motile cellular extensions which project from the outer surfaces of certain cells.
Function: Movement of substances across the surface of cells

Question 13

Structure and function of flagella

Answer 13

Structure: Similar to cilia but longer. Only found on human sperm cells.
Function: Moves the cell itself. Motility.

Question 14

Structure and function of microvilli

Answer 14

Structure: Extensions of the plasma membrane. A lot smaller than cilia (1 to 1/10).
Function: Increasing the cells surface area. (Cells of intestines).