Plasma Membrane & Molecules

Question 1

What are the four main elements found in the human body?

Answer 1

Oxygen, carbon, hydrogen, and nitrogen.

Question 2

Identify an atoms three particles, their charge and their location.

Answer 2

Electrons (-) are found in the shells outside the nucleus.

protons (+) and neutrons are in the nucleus of the atom

Question 3

What is a molecule?

Answer 3

A combination of atoms held together by bonds

Question 4

What is the valence shell? How many electrons can exist within an atoms valence shell?

Answer 4

The valence shell is the outermost level of an Adam that contains electrons they can hold eight electrons

Question 5

Describe the fluid Mosaic model of membrane structure

Answer 5

Model that proposes that membranes are not rigid with molecules locked into place, but rather consist of proteins that move around within a mixture of lipid molecules that has the consistency of olive oil. Proteins in a fluid lipid bilayer

Question 6

What is meant by the term membrane asymmetry

Answer 6

Proteins and other components of 1/2 of the lipid bilayer are different from those that make up the other half of the bilateral

Question 7

What are two major pieces of experimental evidence that support the fluid Mosaic model of membrane structure?

Answer 7

Study done by David Fry and Michael edidin that shows that membranes are fluid.

Experiment that use the phrase facture technique in combination with electron microscopy that showed membrane asymmetry

Question 8

What is the lipid bilayer made out of?

Answer 8

Phospholipid molecules, each consisting of a head group attached to two long chains of carbon and hydrogen (hydrocarbon) called fatty acids

Question 9

What is amphipathic?

Answer 9

Refers to the phospholipid by layer. It is a molecule that contains a region that is hydrophobic and a region that is hydrophilic.

Question 10

What are the 4 key functions of membrane proteins?

Answer 10

1. transport
2. enzymatic activity
3. signal transduction and 4. attachment/recognition

Question 11

What are integral membrane proteins?

Answer 11

Proteins that are embedded in the phospholipid bilayer

Question 12

What are the two major classes of membrane proteins?

Answer 12

Peripheral membrane proteins.

And integral membrane proteins

Question 13

What are peripheral membrane proteins?

Answer 13

Membranes that are positioned on the surface of a membrane and do not interact with the hydrophobic core

Question 14

What are integral proteins?

Answer 14

Proteins that reside within the hydrophobic core of the lipid bilayer. Usually extend through the bilayer to Span both sides. Has both hydrophobic regions and hydrophilic regions of protein on amino acid chain

Question 15

What occurs during a dehydration synthesis reaction?

Answer 15

One water molecule is created from two molecules creating a covalent bond. This requires energy. For example the building block used to make protein is amino acid, amino acids are bonded together via a peptide bond.

Question 16

What are the four levels of protein structure?

Answer 16

1. Primary structure
2. secondary structure
3. tertiary structure and
4. quaternary structure

Question 17

What is the primary structure of a protein?

Answer 17

This is simply the amino acid chain. The sequence of amino acids

Question 18

What is the secondary structure of a protein?

Answer 18

Results from hydrogen bonding between the amino group of one amino acid in a protein chain with the carboxyl group of another amino acid in the protein chain. Regions of an alpha helix or beta sheet and in some cases a particular loop for coil.

Question 19

What is the tertiary structure of a protein?

Answer 19

Overall three-dimensional folding of a polypeptide chain.
In many cases, this is the final stage. It occurs due to the interactions between the variable our side groups. Charged amino acids interact and cause folding

Question 20

What is the quaternary structure of a protein?

Answer 20

This is the interaction of several protein chains, each with its primary, secondary and tertiary structure.

Question 21

What is the main determinant of a protein function?

Answer 21

Combination of the different structures that produces the final protein and relates to its function

Question 22

What do you need mutation has occurred, resulting in a change to the primary structure of the encoded corresponding protein. Why am I changing the primary structure change those proteins function? Why might it not change the function?

Answer 22

Primary structure of a protein is the order of the amino acids in the polypeptide chain. Change in amino acid’s may change the charge and effect of the protein folds that’s affecting the function. It’s possible that the charge on the mutation could be the same which would mean there’s no change in folding and no change in function this is called a conservative change

Should also consider that where the amino acid change happens is important as well as the specific amino acid that is changed

Question 23

What are membrane carbohydrates?

Answer 23

Carbohydrates that are added a short branched chains of monosaccharides to membrane proteins in the membrane lipids.

Question 24

What do membrane carbohydrates do?

Answer 24

Function in cellular recognition and targeting

Question 25

What is the function of a carbohydrate?

Answer 25

Carbohydrates are an energy source of carbon to synthesize other molecules ( proteins, lipids etc.)

In terms of the cell membrane, carbohydrates are for signalling and recognition

Question 26

What are three cellular examples of carbohydrates?

Answer 26

Starch, cellulose, glucose

Question 27

Describe the structure of a carbohydrate

Answer 27

Contains the elements hydrogen, carbon, and oxygen. With the functional groups hydroxyl and Carbonyl. Have lots of oxygen molecules therefore they are often polar

Question 28

What is the term given to a monomer of a carbohydrate?

Answer 28

Monosaccharide which means one sugar

Question 29

How do monosaccharides differ?

Answer 29

Length of the carbon skeleton, location of functional groups, ring structure.

Question 30

What are the terms given to carbohydrate polymers?

Answer 30

Disaccharides and polysaccharides.

Question 31

What process is used to create disaccharides and polysaccharides?

Answer 31

Do you hydration is because this creates the sugar chain

Question 32

What is the bond between monosaccharides called?

Answer 32

A glycocidic linkage

Question 33

What storage polysaccharide is synthesized by photosynthetic organisms?

Answer 33

Starch.

• Glucose units are bonded in 1,4 glycocidic linkage.
• Helical polymer structure is created

Question 34

What storage polysaccharide is synthesized in animals?

Answer 34

Glycogen