Cell biology

Question 1

What are the 6 most common elements in organic molecules

Answer 1

1. oxygen
2. carbon
3. hydrogen
4. nitrogen
5. phosphorous
6. sulphur

Question 2

Define tissue

Answer 2

Groups of cells with interconnected function

Question 3

Define organ

Answer 3

Structures consisting of at least two tissue types which perform a specific function related to the whole body

Question 4

What are organ systems?

Answer 4

Groups of organs performing related functions allowing maintenance of homeostasis

Question 5

What is the general physiology of cells?

Answer 5

1. Respiration to make ATP
2. Exchange gasses
3. Divide and grow
4. Secrete useful/important proteins
5. Communicate with other cells

Question 6

What features are in the general anatomy of cells?

Answer 6

1. Phospholipid cell membrane
2. Membrane bound organelles and nucleus
3. Cytoskeleton
4. Cytoplasm/cytosol

Question 6

What is the function of the nucleolus?

Answer 6

The site where ribosomes are made and transported out into the cytoplasm

Question 6

What are the functions of the phospholipid bilayer?

Answer 6

1. Control movement of substances in and out
2. Keep atoms and molecules at optimum conc. in and out of cell
3. Needed by all cells to perform specialised function

Question 7

What is the phospholipid bilayer permeable to?

Answer 7

1. Water
2. Small molecules (e.g. gasses)

Question 8

What is the phospholipid bilayer impermeable to?

Answer 8

1. Ions - repelled by hydrophobic fatty acids
2. Large molecules (e.g. glucose)

Question 9

What are the roles of membrane proteins?

Answer 9

1. Control transport of ions/larger molecules in and out of cell
2. Intercellular communication
3. Let cells respond to stimuliW

Question 10

What are electrolytes?

Answer 10

Substances in our diet which dissolve/disassociate into their ionic forms in water, allowing us to have the ions our body needs for functioning

Question 11

What are the 4 important ions in cellular physiology?

Answer 11

1. Sodium (Na+)
2. Calcium (Ca+)
3. Potassium (K+)
4. Bicarbonate (HCO3)

Question 12

What is the role of sodium in the body?

Answer 12

1. Maintaining extracellular fluid volume
2. Regulating membrane potential of cells (needed for neuron excitability)
   Main;y extracellular

Question 13

What is the role of potassium in the body?

Answer 13

Regulating membrane potential of cells (needed for repolarisation)
Mainly intracellular

Question 13

What is the role of calcium in the body?

Answer 13

1. Skeletal mineralisation
2. Muscle contraction
3. Synaptic transmission
4. Blood clotting
   Mainly extracellular

Question 14

What is the role of bicarbonate in the body

Answer 14

1. Buffer to keep pH neutral for most cell reactions to occur by binding to excess hydrogen ions produced in cellular reactions
   Mainly extracellular

Question 15

What is plasmolysis?

Answer 15

Changes in ion conc. leading to water being drawn into or out of a cell

Question 16

What is CFTR

Answer 16

Defect in Cystic Fibrosis Transmembrane Regulator protein resulting in cystic fibrosis by preventing Cl- moving out of the cell, so water moves in by osmosis and mucus on cell surface membrane dries up

Question 16

What are the different types of intercellular signalling?

Answer 16

1. Endocrine signalling
2. Paracrine signalling (nearby cell)
3. Autocrine signalling (targets itself)
4. Synaptic signalling
5. Cell membrane protein signalling (direct contact)

Question 17

What happens in intracellular signaling?

Answer 17

Receptor on cell surface sends signal to nucleus to switch on genes
Can be targeted by drugs (e.g. in tumour growth)