Cells and Tissues

Question 1

What are the 3 parts a cell can be divided into?

Answer 1

1. Plasma (cell) membrane  forms a boundary between what’s inside and outside of the cell
2. Cytoplasm
   - Cytosol  liquid part
   - Organelles  functioning machinery that’s embedded within the cell
3. Nucleus
   - Chromosomes/ genes
   - Nucleolus

Question 2

What makes up the Nucleus?

Answer 2

o Chromatin - DNA
o Nuclear pore - allow for the exit of the information from the DNA (mRNA)
o Nuclear envelope - defines the boundary of the nucleus
o Nucleolus - organelle found within the nucleus which helps make ribosome

Question 3

What makes up the cytoplasm?

Answer 3

o Cytosol
o Organelles (except nucleus)

Question 4

What is the function of the Rough endoplasmic reticulum (ER)?

Answer 4

o Network
o Has ribosomes on it (produce proteins)

Question 5

What is the function of membrane bound ribosomes?

Answer 5

Produce proteins

Question 6

What is the function of the Golgi complex?

Answer 6

Once the protein is produced by the ribosome and processed in the rough endoplasmic reticulum, the protein is further packaged up in the Golgi apparatus (prepares proteins for use in other places inside and outside of the cell)

Question 7

What is the function of the mitochondrion?

Answer 7

Powerhouse of the cell / the energy used throughout the cell

Question 8

What is the function of the smooth endoplasmic reticulum?

Answer 8

o Lacks membrane bound ribosomes
o Produces phospholipids (vital molecule required to produce the cell membrane (plasma membrane))

Question 9

What is the function of the lysosome?

Answer 9

Breaks up debris (dysfunctional proteins/ deformed proteins) within the cell

Question 10

What is the function of the lysosome?

Answer 10

Breaks up debris (dysfunctional proteins/ deformed proteins) within the cell

Question 11

What is the function of the plasma membrane?

Answer 11

o Boundary that defines what is within and outside cell
o A flexible yet sturdy barrier that surrounds and contains the cytoplasm of the cell.
o Made up of phospholipid bi-layer

Question 12

What is the function of the cytoskeleton?

Answer 12

Skeletal framework / shape and structure.
o Microtubules - they traverse the length and breadth of the cell. Highways and pathways in the cell.
o Microfilaments - help in the movement of a cell.
o Intermediate filaments - provide tensile strength to the cells.

Question 13

What is the function of the microvilli?

Answer 13

Increase surface area. Helps in the absorption of nutrients in the intestines.

Question 14

What is the function of the flagellum?

Answer 14

Help in the motility of the cell. E.g., sperm cell

Question 15

What is the function of the cilium?

Answer 15

Moves about itself without the cell moving. Moves things around in the cell. E.g. too much mucus in the cell – cilium will help move the mucus away from the cell membrane

Question 16

What makes up the plasma membrane?

Answer 16

o Make up of lipid bi-layer - composed of phospholipids
o Cholesterol – gives rigidity to the plasma membrane
o Proteins
- Integral proteins / transmembrane proteins - signal transduction
- Peripheral proteins - enzymatic reactions (in the cell (intracellular) or out of the cell (extracellular))
- Glycoproteins - identity markers (let the immune cells in the body know where the cell belongs / protects cell from being attacked by the immune cells)

Question 17

What is the membrane permeability of the plasma membrane?

Answer 17

o Plasma membranes are selectively permeable
- Lipid bilayer is always permeable to small, nonpolar, uncharged molecules (e.g. oxygen)
- Transmembrane proteins that act as channels or transporters increase the permeability of the membrane (form the channels that allow molecules to pass through cell membrane e.g. glucose)
- Macromolecules are only able to pass through the plasma membrane by vesicular transport

Question 18

What are the two gradients across the plasma membrane?

Answer 18

Concentration gradient and Electrical gradient

Together, make up an electrochemical gradient.

Question 19

What is concentration gradient?

Answer 19

The difference in the concentration of a chemical between one side of the plasma membrane and the other

Question 20

What is electrical gradient?

Answer 20

The difference in the concentration of ions between one side of the plasma membrane and the other

Question 21

What are the three passive processes of transport across the plasma membrane?

Answer 21

• Simple diffusion
• Facilitated diffusion
• Osmosis

Question 22

What are the two active processes of transport across the plasma membrane?

Answer 22

• Active transport
• Vesicular transport

Question 23

What is simple diffusion?

Answer 23

o Doesn’t require the use of energy (ATP)
o Influenced by factors:
- Steepness of the concentration gradient
- Temperature
- Mass of diffusion substance
- Surface area
- Diffusion distance

Question 24

What is facilitated diffusion?

Answer 24

o Molecules move from a region of high concentration to low concentration
o Facilitated by a channel (aquaporins)

Question 25

What is Osmosis?

Answer 25

o The net movement of a solvent through a selectively permeable membrane from an area of high concentration to an area of low concentration

Question 26

What is tonicity?

Answer 26

o Related to how the concentration of solute in the solution influences the shape of body cells.

o Hypertonic - high concentration outside cell
o Isotonic - equal concentration inside and outside of cell
o Hypotonic - high concentration inside cell

Question 27

What is active transport?

Answer 27

Energy derived from ATP changed the shape of a transporter protein which pumps a substance across a plasma membrane against its concentration gradient.

Question 28

What are the 4 types of tissue?

Answer 28

Epithelial, Connective, Muscular, Nervous

Question 29

What are the types of epithelial tissue?

Answer 29

Layers:
Simple
Stratified
Pseudostratified

Shape:
Squamous
Cuboidal
Columnar
Transitional