Virus/cell Membrane☘️🌿

Question 1

What’s a virus?

Answer 1

-Are acellular
-So they are not cells they are are nucleid acid surrounded by a protein
-They are not living
-Are smaller than bacteria(0.1 nanometer less in diameter)
-All viruses will invade and reproduce in a host cell

Question 2

List the components in a virus?

Answer 2

Envelope protein
Envelope
Viral genome
Nuclecapsid
Viral tegument

Question 3

What is the viral genome?

Answer 3

It is all the genetic material of virus
-It is nucleic acid:
core genetic material can be made of DNA or RNA and viruses can be classified on this (virus and RNA without DNA= retrovirus)

Question 4

What is a nucleocapsid?

Answer 4

Protein coat surrounds the core genetic material of virus

Question 5

What is an envelope protein?

Answer 5

Are attachment proteins which allow the virus to cling to a suitable host

Question 6

What is an antigen?

Answer 6

Part of an organism which can be a substance which recognised as non self by immune system (complementary)
can be proteins, carbohydrates, or other molecules found on the surface of pathogens like bacteria, viruses.

Question 7

What term is given to bacterial shape?

Answer 7

Cocus

Question 8

What are present in eukaryotic cell

Answer 8

They are alive
-nucleus
-lysosomes
-ER
-mitochondria
-chloroplast
-Golgi
-Vacuole
-cell wall
- ribosome
-flagellum
-genetic material

Question 9

What are present in prokaryotic cell?

Answer 9

-plasmids
-ribosome
-capsule
-mesosome
-capsule
-cell wall and membrane
-cytoplasm

Question 10

What are present in virus?(HIV)

Answer 10

glycoprotein
Phospholipids(membrane)
Reverse transcriptase
RNA

Question 11

What are the many functions of cell membrane

Answer 11

1-regulates control the entry and exit of materials e.g mitochondria and chloroplasts
2-isolate organelle so that specific metabolic reactions can take place within them
3-isolate enzymes that might damage the cell
4-provides an internal transport system e.g ER

Question 12

What happens when you put a drop of oil in water?

Answer 12

Oil droplets from a circular shaped or layer(not mixed with water)
-oil molecule are hydrophobic
-water molecules are hydrophilic

Question 13

What is the cell membrane made up of?

Answer 13

-GlycoLipids
-Cholesterol
-Phospholipids bilayer and transport proteins

Question 14

What are Phospholipids bilayer composed of?

Answer 14

-A hydrophobic tail(inside)attract to fats and not to water
-A hydrophilic head(out) attract water not fats
The extracellular interact with and phospholipids outer layer and intercellular interacts with inner phospholipids layer which both contains aqueous solutions(contains water)

Question 15

What is phospholipids function?

Answer 15

-Make membrane flexible
-allow lipids soluble to enter and leave cell as they are hydrophobic they can move within and exit/enter very easily
-don’t allow water soluble to enter or leave cell
(Selective permeability
While others substances require specific transport of mechanisms to cross the membrane,

Question 16

What 2 structures can a phospholipids form when exposed to water?

Answer 16

Micelle(circle)
Or bilayer (phospholipids mirroring each other)
In both the head is facing water whilst the tail is away from water.

Question 17

Why is it called fluid mosaic model to describe the arrangement of plasma membrane ?

Answer 17

Fluid:cause individual phospholipids can move relative to each other (makes it flexible)
Mosaic:proteins within the bilayer vary in size shape and pattern just like mosaic tiles.

Question 18

Draw a micelle and explain why it forms this way

Answer 18

Phospholipids have a polar hydrophilic head and a non-polar hydrophobic tail. These gather to ‘protect’ the tails from the aqueous solution by the heads forming a ring all facing out.

Question 19

What is material is 1 phospholipid made of?

Answer 19

Choline(r group)
Phosphate
Glycerol
Fatty acids

Question 20

Specialized cells have adaptations that optimize the rate of transport across their internal and external membranes to meet specific physiological needs

Answer 20

S.A: Some cells have microvilli or villi, which are finger-like projections that increase the surface area of the cell’s external membrane.A larger surface area allows for more efficient transport of substances.(absorption)
-Selective Permeability: Cell membranes are selectively permeable, meaning they allow specific molecules to pass through. This selectivity is essential for maintaining proper conditions within the cell and is regulated by membrane proteins
-Active Transport: Some cells, like those in the kidneys, have adaptations for active transport, which requires energy (usually ATP) to move substances against their concentration gradients. This is crucial for reabsorption and secretion of specific ions and molecules.
-Cilia and Flagella: Some cells, like sperm cells, are equipped with cilia and flagella for motility. These structures help transport the cell itself or substances around it.
-Receptor Proteins: Cells like immune cells have receptor proteins on their membranes to detect specific molecules. This helps them identify and respond to pathogens or foreign substances.(glycoprotein)
-Mitochondria: Cells with high energy demands, such as muscle cells, have numerous mitochondria to provide ATP for active transport processes and other energy-consuming functions.