Robustness And Adaptation

Question 1

What is robustness

Answer 1

Ability of cell to maintain Performance and function in face of internal and external perturbations

Question 2

What characteristic of cells allows them to adapt to changes in their environment?

Answer 2

Dynamic

Question 3

Cells have a feature that enables them to withstand failures. What is this feature called?

Answer 3

Redundancy

Question 4

Cells are able to maintain function despite errors or failures. This ability is known as _______.

Answer 4

Fault tolerance

Question 5

What can slight increases in temperature be beneficial for?

Answer 5

Short term benefits

Slight increases in temperature may enhance certain physiological responses.

Question 6

What role does fever play during infection?

Answer 6

Helps the immune response by:
* Increased movement of white blood cells
* Increased proliferation of white blood cells (T cells)
* Enhanced rate of phagocytosis

Fever is a natural response to infection that aids in fighting pathogens.

Question 7

At higher temperatures, what problems do cells encounter?

Answer 7

Cells become stressed
Most enzymes optimised to work at 37 degrees
Cell membrane becomes more fluid
Proteins domt fold properly
## Footnote

Higher temperatures can disrupt normal cellular functions.

Question 8

How does increased temperature affect the cell membrane?

Answer 8

Becomes much more fluid

Fluidity of the membrane can impact its integrity and function.

Question 9

How do membranes respond to heat

Answer 9

Change lipid composition of membrane by adding more saturated fatty acids ( makes membrane more viscous ) and add cholesterol ( aids stability of membrane)

Question 10

What determines what genes are essential for optimal growth

Answer 10

Environmental conditions
Which other genes are also expressed

Question 11

What are heat shock proteins?

Answer 11

Heat shock proteins are a group of proteins produced when a cell is exposed to elevated, sub-lethal temperatures.

Question 12

What do heat shock proteins do?

Answer 12

They protect the cell from lethal temperature rises if exposed subsequently.

Question 13

When do heat shock proteins increase in expression?

Answer 13

They increase in response to other stresses such as deprivation of oxygen or nutrients.

Question 14

What is the main function of heat shock proteins?

Answer 14

Their main function is to help proteins fold properly so that they can function properly.

Question 15

Problems caused by cold temp

Answer 15

Slow enzyme reactions
Rigid viscous membrane
Ice crystals

Question 16

What are proteins with sugars attached called?

Answer 16

Glycoproteins

Glycoproteins are formed through a process known as glycosylation.

Question 17

What is the process of attaching sugar to proteins called?

Answer 17

Glycosylation

Glycosylation is a post-translational modification.

Question 18

Where are many glycoproteins located?

Answer 18

In the plasma membrane

The carbohydrate region of glycoproteins is presented outside the cell.

Question 19

What is the function of the attached sugars in glycoproteins?

Answer 19

To stabilize protein structure

This stabilization offers protection from the extracellular environment.

Question 20

What are glycolipids?

Answer 20

Lipids with sugars attached

Glycolipids are present in the plasma membrane and provide protective functions.

Question 21

Fill in the blank: Glycoproteins are formed through a process known as _______.

Answer 21

Glycosylation

Question 22

True or False: Glycolipids and glycoproteins have similar protective functions.

Answer 22

True

Question 23

What type of modification is glycosylation?

Answer 23

Post-translational modification

Question 24

Where are carbohydrates attached to proteins?

Answer 24

In the rough ER

Rough endoplasmic reticulum (ER) is involved in protein synthesis and modification.

Question 25

What type of bond links a carbohydrate to a protein?

Answer 25

A glycosidic bond ## Footnote Glycosidic bonds are formed between carbohydrates and other molecules.

Question 26

Which amino acid is associated with N-linked glycosylation?

Answer 26

Asparagine ## Footnote N-linked glycosylation refers to the attachment of carbohydrates to asparagine residues.

Question 27

Which amino acids are associated with O-linked glycosylation?

Answer 27

Serine or threonine ## Footnote O-linked glycosylation involves the attachment of carbohydrates to serine or threonine residues.

Question 28

Feature of pyschrophiles

Answer 28

Have proteins and metabolism optimised for cold temperatures Proteins structurally more flexible Metabolism slower

Question 29

What happens to oxygen concentration as the distance from blood vessels increases?

Answer 29

Oxygen concentration decreases quickly as the distance from blood vessels increases.

Question 30

When does general hypoxia occur

Answer 30

Environmental oxygen levels low Anaemia In premature babies (undeveloped lungs) Poisoning( cynaide or co)

Question 31

When does local hypoxia occur

Answer 31

Ischaemia ( blood supply cut off following heart attacks ) Cancer ( tumour collapses blood vessels )

Question 32

What is the cellular response to hypoxia

Answer 32

Transcription factors (HIFS) move to nucleus and alter gene expression Cell cycle stops at G1 Cell switches to glycolysis and anaerobic metabolism to produce ATP rapid down regulation of protein synthesis In prescience of oxygen : HIFS degraded by proteasomes

Question 33

In response to hypoxia cells release hypoxia response genes. How do they work.

Answer 33

Genes - growth factors -> stimulate nearby blood vessels to branch off and move to hypoxia cells which delivers oxygen to area.

Question 34

What is quiescence

Answer 34

State of reversible cell cycle arrest giving protection against nutrient deprivation starvation low temp and low oxygen Associated w low metabolic state characteristiced by low glucose uptake and glycolysis reduced protein intake and activation of autophagy as a means to provide nutrients

Question 35

How does autophagy help cell repsond to stress

Answer 35

Cells form double membranes vesicles called autophagosomes that take organelles to lysosome where degradative enzymes eliminate damaged components and cell recycle constitute to for energy

Question 36

Where does membrane of autophagosomes come from

Answer 36

Existing organelles like ER and Golgi which allow for rapid formation in response to stress

Question 37

What is protesome role

Answer 37

Multi proteins complexes that degrade damaged proteins and recycle amino acids for more protein synthesis Important in stress response if heat shock infection and oxidative stress

Question 38

What is dna damage response

Answer 38

Crucial bc permanent mutations are formed - cell cycle checkpoint Transcriptional program sctivation Dna repair If damage irreversible apoptosis