Unit 13: Cell Signalling and Blood

Question 1

The process in which antibodies attach to antigens, causing the formation of masses of linked cells is called:

Answer 1

Agglutination

Question 2

An individual has previously given birth to a baby. In a subsequent pregnancy, hemolytic disease of the newborn would most likely be a risk in the following case :
1) The person carrying the fetus is A-
2) The person carrying the is AB+
3) The fetus is O-
4) The first child is B-

Answer 2

1) The person carrying the fetus is A-

Question 3

The SAFEST blood to give to a person with AB- blood is:

Answer 3

AB-

Question 4

Why are ion channels necessary to transport ions into or out of a cell?

Answer 4

Ions are charged particles and cannot diffuse through the hydrophobic interior of the membrane.

Question 5

A person living with hemophilia will bleed more easily because they have:

Answer 5

inadequate clotting factors

Question 6

A patient has been prescribed, warfarin, an anticoagulant. This medication will help to:

Answer 6

reduce blood clotting

Question 7

In the coagulation cascade, the common pathway occurs:

Answer 7

AFTER both the intrinsic and extrinsic pathway

Question 8

In some breast cancers, a cell membrane receptor called HER2 is overexpressed (ie. there are more than usual). The dimerization of this protein can cause cell proliferation and growth, which in cancer, leads to tumour growth. Direct treatment for this type of cancer might include:

Answer 8

Medication that binds to HER2 and blocks its signaling

Question 9

Match the type of signal with its characteristics:

Signals from distant cells

Answer 9

Endocrine

Question 10

Match the type of signal with its characteristics:

Move by diffusion through extracellular matrix

Answer 10

Paracrine

Question 11

Match the type of signal with its characteristics:

Intracellular mediators that allow small signaling molecules to move between cells

Answer 11

Gap junction signalling

Question 12

Match the type of signal with its characteristics:

Signal and target cell are the same

Answer 12

Autocrine

Question 13

The toxin from this illness enters intestinal cells and modifies a G-protein-linked receptor that controls the opening of a chloride channel. This causes the channel to remain continuously active, resulting in large losses of fluids from the body and potentially fatal dehydration as a result.

Answer 13

Cholera

Question 14

A cell surface receptor protein would most likely include the following component:

Answer 14

An extracellular domain

Question 15

Clotting factors are numbered sequentially based on:

Answer 15

The time of their discovery

Question 16

The insoluble filamentous protein derived from fibrinogen that is essential for clotting is called:

Answer 16

Fibrin

Question 17

Lupus, sickle cell disease, and pregnancy might all increase the risk of developing:

Answer 17

Thrombophilia

Question 18

Internal Receptors

Answer 18

• In the cytoplasm.
• Respond to hydrophobic ligand molecules that are able to travel across the plasma membrane.
• The ligand molecules bind to the proteins that act as regulators of mRNA synthesis to mediate gene expression.
• Triggers a conformational change that exposes a DNA-binding site on the protein.

Question 19

Cell-Surface Receptors

Answer 19

• On cell surface in the plasma membrane.
• Proteins that bind to external ligand molecules that cannot cross the plasma membrane.

Question 20

Ion Channel-Linked Receptors

Answer 20

• On cell surface in the plasma membrane.
• Bind to a ligand and then a membrane channel opens that allows specific ions to pass through.
• Amino acids line the inside of the channel and are hydrophilic to allow passage of water or ions.

Question 21

Small Hydrophobic Ligands

Answer 21

• Can directly diffuse through the plasma membrane and interact with internal receptors.
• Includes steroids (like estradiol(form of estrogen), testosterone, cholesterol, and other hydrophobic hormones like thyroid hormones and vitamin D.

Question 22

Water-Soluble Ligands

Answer 22

• Cannot pass through the plasma membrane unaided (polarity) or at all (some are too large)
• Bind to the extracellular domain of cell-surface receptors.
• This group of ligands is quite diverse and includes small molecules, peptides, and proteins.

Question 23

Other Ligands

Answer 23

• Nitric oxide (NO) is a gas that diffuses directly across the plasma membrane to interact with receptors in smooth muscle and induce relaxation of the tissue.
• NO has a very short half-life and, therefore, only functions over short distances.