01. Chemical, Cellular, Tissue Organisation & The Integumentary System

Question 1

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Which are the 3 most important
macromolecules in the cells?

Answer 1

RNA
DNA
Protein

Question 2

What is the primary function of DNA, RNA and Protein?

Answer 2

DNA is a polymer of nucleic acids that stores information coded by specific base pairing.
RNA is a polymer of nucleic acids that converts DNA into a usable format by the cell (Protein). Proteins are polymers of amino acids that form biomolecules with diverse functions.

DNA –> RNA –> Protein

Question 3

Describe the 3 main mechanisms of transport across the plasma membrane.

Answer 3

1. Simple Diffusion: small molecules and gasses move through from high to low concentration.
2. Passive Transport: Larger molecules (eg. glucose) and charges ions are transported through protein channels from high to low concentration.
3. Active Transport: Similar to Passive but against the consentration gradient, thus require ATP.

Question 4

Can be collagen, elastic or reticular in nature. Provides a structural role.

Answer 4

Fibers

Question 5

Composed of water and organic molecules, may be fluid, gelatinous or calcified, provides a medium to support the cells.

Answer 5

Ground Substance

Question 6

Produce histamine as part of the immune response. Can become over sensitive in cases of allergies.

Answer 6

Mast Cells

Question 7

Large cell that eats potential invaders or parts of dead or dying cells.

Answer 7

Macrophages

Question 8

Part of the adaptive immune system.

Answer 8

Plasma Cells

Question 9

Which of the following cellular connections is not between two neighboring cells?
a. Hemidesmosome
b. Gap Junction
c. Adherens Junction
d. Tight Junctions
e. Desmosome

Answer 9

a. Hemidesmosome.
Related to Desmosomes but does not connect neighboring cells. The Hemidesmosome connxts a cell to the Basement Membrane. Have a similar plaque structure on the inner plasma membrane but the attachment proteins are Integrins and not Cadherins.

Question 10

Which of the following forms a ‘‘water tight’’ connection between cells?
a. Tight Junctions
b. Desmosome
c. Hemidesmosomes
d. Gap Junction

Answer 10

a. Tight Junctions
Glycoproteins called occludins and claudins create tight junctions between cells. Very prominent in organs that contain liquids.

Question 11

Which organelle (in addition to the nucleus) has their own genome?

Answer 11

Mitochondria

The mitochondria is a double membrane organelle responsible for the majority of energy production in the cell. It contains a small genome. Endosymbiotic theory suggests that our mitochondria was once a living bacteria that was engulfed by our ancestor cell. It retained a portion of its DNA genome and continues to make some of its own proteins. However the majority of mitochondria proteins are encoded in the nucleus.

Question 12

itochondria generate the majority of energy in the cell. One of the main chemical reactions that mitochondria catalyze is…

Answer 12

the breakdown of glucose in the presence of oxygen to give carbon dioxide, water and energy.

Glucose + O2 –> Energy + CO2 + H2O

Question 13

The main function of the Lysosome is…

Answer 13

The breakdown of macro-molecules using digestive enzymes.

Question 14

Which of the following statements are true about the Plasma Membrane?

a. Cholesterol is not an important part of the plasma membrane.
b. The plasma membrane is composed of amphipathic molecules.
c. The plasma membrane is impermeable to all molecules
d. The plasma membrane is composed of phospholipids.

Answer 14

b.The plasma membrane is composed of amphipathic molecules.
Amphipathic means ‘‘dual properties’’ ie both hydrophobic and hydrophilic.

Question 15

The main function of the Golgi Apparatus is…

Answer 15

A sorting body that prepares proteins for secretion outside of the cell.

Question 16

In what part of a cell would you find most of a cell’s genetic material?

Answer 16

Nucleus

Question 17

The cytoplasm of a cell is made up of…

Answer 17

the cytosol and organelles

Question 18

Which membrane proteins are involved with the transport of molecules that otherwise would be unable to enter the cell?

Answer 18

carrier proteins

Question 19

Which of the following best describes the basic structure of the plasma membrane?
a. glycocalyx
b. selective permability
c. phospholipids
d. glycoproteins
e. Lipid bilayer

Answer 19

e. Lipid bilayer

Question 20

Pseudostratified epithelial cells are defined by their organization. The defining characteristic of pseudostratified epithelial cells is…

Answer 20

All cells are attached to the basement membrane but only some cells reach the apical surface.

Question 21

Which of the following is correct about Epithelial Tissues.

a. Exocrine Epithelial glands secrete substances directly into blood circulation.
b. Epithelial Tissue tends to be tightly packed.
c. Epithelial Tissue can be classified as Covering & Lining or Glandular.
d. Epithelial Tissue has a lot of vascularization and blood vessels.
e. The main role of Epithelial Tissue is as a support network.

Answer 21

c. Epithelial Tissue can be classified as Covering & Lining or Glandular.

Depending on the role, some epithelial acts as a barrier, glandular epithelial is involved in the secretion of substances such as hormones.

Question 22

Name the 3 types of Epithelial Membranes

Answer 22

Mucous
Serous
Cutaneous

Question 23

The major energy molecule in the cell is
a. ATP
b. Lipids
c. Carbohydrates
d. Protein

Answer 23

ATP

This is a mean question since lipids, carbohydrates and proteins are an energy source! But the main energy molecule (currency) of the cell is ATP. ATP contains a Triphosphate group which contains a high energy electron. When the bond between the terminal phosphate is broken the electron drops down to a lower energy state releasing energy that can be used to power enzymatic reactions.

Question 24

Mitochondria are unusual for organelles since

Answer 24

The have a DNA genome

Question 25

The epidermis is an example of a vascular tissue (True/False)?

Answer 25

False

The epidermis is an example of an avascular tissue (no blood vessels). The nutrient and oxygen required is supplied by the dermis. Consider that the main function of the epidermis is as a barrier, it make sense that it would be avascular (otherwise pathogens that break into the epidermis would have easy access to the body).