Mebrance Structure, Function And Transport

Question 1

What are your main components of your cell membranes?

Answer 1

Phospholipids - also know as being amphipathic (because of its hydrophobic and hydrophilic nature)
Proteins
Cholesterol
Glycolipids
Glycoproteins

Question 2

What are some some other ways in which a cell membrane is know as

Answer 2

Plasmalemma or Plasma Membrane

Question 3

What are some functions your cell membranes carry out

Answer 3

It serves as a protective covering (barrier) separates the inside of the cell from the outside, which creates a distinct structure.
Allows communication with other cells/organelles.
Due to its semi permeable membrane it regulates movement of substances across its surface.
Helps maintain an appropriate internal environment which is needed to carry out various chemical reactions.

Question 4

What are the two types of membrane and give examples of each.

Answer 4

Single membrane organelles
ER, Golgi, lysosomes, vesicles and vacuoles
Double membrane organelles
Chloroplast,mitochondria and nucleus

Question 5

What is the structure of a phospholipids

Answer 5

Glycerol
2 fatty acids
Phosphate group
Organic substance(choline)

Question 6

Proteins in the membrane

Answer 6

Proteins are located on the cell membrane surface or embedded between the phospholipid by layer.

Plasma membranes and organelle members have have unique proteins.

The proteins that are attached or embedded in our cell membranes is what determines the function that membrane will carry out and they are oriented asymmetrical across the bilayer.



Question 7

What are the two types of proteins.

Answer 7

Integral [intrinsic] proteins - these proteins or firmly bound to the membrane. And they can span a membranes either partially or completely. Integral proteins that completely goes through a membrane are know as transmembrane.

Peripheral(extrinsic) proteins- These proteins are located on the inner or outer surface of the bilayer of cell membrane and can be easily removed. Some often binds to expose parts of integral proteins.

Question 8

What are some functions of proteins in membrane.

Answer 8

Structural support
Transports
Enzymes
Receptors
Recognition markers

Question 9

What are the functions of glycoproteins and glycolipids?

Answer 9

Glycolipid and glycoproteins are lipids or proteins that are attached to a carbohydrate. These substances are found on the outside of cell membranes and are used in cell recognition and receptors for chemical signals.
Glycolipids facilities cellular recognition while you’re glycoproteins serves as receptors for chemical signals.

Question 10

Why is cholesterol needed in cell membrane?

Answer 10

Cholesterol is needed in our cell membranes to provide stability. It limits and maintain the fluidity of a cell and It is embedded within phospholipids. (Because they are fats they embeds themselves in the hydrophobic parts of the phospholipids)

Question 11

How does the transport of substances occur in remembrance

Answer 11

Because our phospholipid bilayer is a semi permeable this allows for certain substances to pass in and out of a membranes. Movement of particles depends on the size lipid solubility and the charge on that particle.(In general members of permeable to small molecules, Non-charged molecules and lipid molecules.
Small polar molecules can easily pass through the cell membranes due to them following their concentration gradient.
Ions and charge molecules have difficulty crossing the hydrophobic phase of the bilayer.

Question 12

What are the two types of transport

Answer 12

Passive transport - is movement of particles from a region of higher concentration to a region lower concentration and does not require energy. 
Active transport – is the movement against the concentration gradient [movement of particles from a region of low concentration to a region of high concentration] and this process requires energy (ATP) and integral proteins.

Question 13

What are the two types of passive transport?

Answer 13

Simple diffusion – substances freely move across membranes or channels are open and materials move through them.
Eg. Water, oxygen, carbon dioxide and glycerol(alcohols)
Facilitated diffusion – transport requires a specific carrier protein that combines temporarily with material and allows it to move through the membrane. Protein is not changed in the process.
Eg. Glucose, amino acids

Question 14

What is the job of transport proteins

Answer 14

A transport protein is one that is involved in the movement of ions small molecules or macromolecules such as another protein across a biological membrane.
Transport proteins are your Integral membrane proteins meaning they exist with in and span the entire membrane across which they transport substances.
Transport proteins me assist in the movement of substances by facilitated diffusion or active transport

Question 15

What is osmosis?

Answer 15

Is the movement of water molecules from a region of high concentration to a region of low concentration through a semipermeable membrane.
The movement of these water particles occur in a hypotonic hypertonic or isotonic solution.

Question 16

How does water move in a hypertonic/plasmolyze situation

Answer 16

The net movement of water will be out of a cell in a hypertonic solution. This means that the external environment of that cell contains more solute than inside the cell. (water moves outside the cell because there is a higher concentration of solutes outside eg. Salts or sugars)

Question 17

How does the net movement of water move in a hypotonic/turgid solution

Answer 17

The net movement of water will be into a cell in a hypotonic solution Which has a lower concentration of solutes than inside the cell.( water moves into a cell because there is a higher concentration of solutes in the cell than its external environment)

Question 18

How does the net movement of water car in an isotonic/flaccid solution?

Answer 18

The net movement of water will be equal in an isotonic solution. [This means that there is an equal concentration of solutes inside and outside of the cell].

Question 19

What is exocytosis

Answer 19

Is the release of material from cells via the fusion of vesicle with the plasma membranes.

Question 20

What is endocytosis?

Answer 20

Materials are taken into the cell by the folding Plasma membrane around.