Huabing (Block 1 ENG in Bio)

Question 1

What is a hydrogen bond ?

Answer 1

A polar interaction in which an electropositive hydrogen atom is
partially shared by two electronegative atoms

Question 2

What is a ionic bond ?

Answer 2

Attractive forces between oppositely charged atoms

Question 3

What is a covalent bond ?

Answer 3

Formed by the sharing of electrons

Question 4

What is Van der Waals attraction ?

Answer 4

the interaction between opposite dipoles of atoms

Question 5

What is the use of Hydrophobic force for bonding ?

Answer 5

Is not a bond, but caused by a pushing of nonpolar surfaces out of the
hydrogen-bonded water network

Question 6

Typical covalent bonds are stronger than thermal energy by a factor of ?

Answer 6

100 therefore not easily pulled apart by heating

Question 7

What type of bonds specify the precise shape of a macromolecule ?

Answer 7

Non-covalent

Question 8

What is a macromolecule ?

Answer 8

A macromolecule is a very large molecule, such as a protein. They are composed of thousands of covalently bonded atoms. … The most common macromolecules in biochemistry are biopolymers (nucleic acids, proteins, and carbohydrates) and large non-polymeric molecules such as lipids and macrocycles

Question 9

What form of movement do covalent bonds allow in a macromolecules and how is this countered ?

Answer 9

Rotational, countered by many non-covalent bonds to hold in place

Question 10

What bonds link amino acids together and what is what is forms called ?

Answer 10

Covalent peptide bonds, together form the polypeptide backbone.

Question 11

What determines the precise shape of a protein ?

Answer 11

It’s amino acid sequence

Question 12

What does the side chain do in a protein ?

Answer 12

The side chain gives each amino acid

unique properties and are involved in forming noncovalent bonds to help proteins fold.

Question 13

What 3 types of non-covalent bonds are used in protein folding ?

Answer 13

Van der waals , Hydrogen bonds and electrostatic bonds (ionic bonds ).

Question 14

What force can be involved in protein folding ?

Answer 14

Hydrophobic forces (when in water ).

Question 15

Proteins generally fold into a shape in which _____ is minimised ?

Answer 15

Free energy

Question 16

What are the most structurally diverse macromolecules in the cells ?

Answer 16

Proteins

Question 17

What are the 2 most regular folding patterns for proteins ?

Answer 17

Alpha helix and the beta sheet

Question 18

What is the primary structure of a protein ?

Answer 18

It’s amino acid sequence

Question 19

What is the secondary structure of a protein ?

Answer 19

Alpha helices and beta sheets that form within certain segments of the polypeptide chain.

Question 20

What is the tertiary structure of a protein ?

Answer 20

The full 3D conformation, is formed

by an entire polypeptide chain, including the alpha helices, beta sheets, and any other folds

Question 21

What is the quaternary structure of a protein ?

Answer 21

The complete structure of a protein ,if the protein is formed out of several polypeptide chains.

Question 22

What is a Protein domain ?

Answer 22

A protein domain is defined as any segment of a

polypeptide chain that can fold independently into a compact, stable structure

Question 23

What is a protein family ?

Answer 23

proteins consisting of similar amino acid sequences and 3D conformation are unusually
grouped as a protein family

Question 24

Larger protein molecules often contain more than one polypeptide chain. Any region on a protein surface that has this capability is termed?

Answer 24

A binding site

Question 25

Each peptide chain in a large protein with multiple chains is called ?

Answer 25

A subunit.

Question 26

In addition to the non-covalent bonds, ___________ between polypeptide chains are often formed to reinforce the structure of proteins (name the most common )

Answer 26

covalent cross-linkages (Disulfide)

Question 27

Any substance that is bound by a protein is referred to as a ______ for that protein

Answer 27

Ligand

Question 28

Each antibody can recognize and bind to a particular target (called an _______) extremely tightly

Answer 28

antigen

Question 29

What shape is an Antibody ?

Answer 29

Y shaped

Question 30

Antibodies are formed from four __________ held together by ________ bonds: two are identical ______ chains and two identical _______ chains.

Answer 30

1 .Polypeptide chains 2. disulfate 3. heavy 4. light

Question 31

The antigen binding site of an antibody is formed by ?

Answer 31

Close association of variable domains from heavy and light chains.

Question 32

Antigen binding site complementary to a site on the antigen (known as the ________) in terms of shape and the arrangement of ________ and _______ groups

Answer 32

1. epitome 2. hydrophobic 3. charged

Question 33

The movements of protein machines is coordinated by what ?

Answer 33

The hydrolysis of a bound nucleoside triphosphate (ATP or GTP).

Question 34

What does the plasma membrane do ?

Answer 34

Acts as a selective barrier to maintain a constant intracellular composition

Question 35

The ___________ senses the external signals and allows the cell to change its behavior in response to the signals

Answer 35

plasma membrane

Question 36

What makes up the lipid bilayer ?

Answer 36

Lipids arranged in two closely apposed sheets. The hydrophilic heads are attracted to the water molecules and the hydrophobic repel.

Question 37

What does the lipid bilayer do ?

Answer 37

Serves as a permeability barrier to most water-soluble molecules

Question 38

Describe a lipid molecule

Answer 38

A hydrophilic head and 1 or 2 hydrophobic hydrocarbon tails known as amphipathic

Question 39

The fluidity of the lipid bilayer depends on what ? And explain how this effects fluidity

Answer 39

On it's composition, the more closely packed the hydrocarbon tails are the more viscus and less fluid the bilayer becomes

Question 40

Read from lecture 4 slide 9 to end These are hard to question on without images.

Answer 40

I did it .

Question 41

Name the 4 types of signaling between cells

Answer 41

Endocrine signaling ,paracrine signaling, neuronal signaling,contact-dependent signaling.

Question 42

Describe endocrine signaling

Answer 42

Endocrine cells secrete hormones into the bloodstream, affecting the target cells anywhere in the body

Question 43

Describe paracrine signaling

Answer 43

The signal molecules diffuse locally through the | extracellular fluid, acting as local mediators

Question 44

Describe neuronal signaling

Answer 44

Neuron cells can deliver electrical signals over long distances

Question 45

Describe contact-dependent signaling

Answer 45

The signal molecules on the surface of the signaling cell are in direct physical contact with the receptor proteins on the surface of the target cells

Question 46

Name and describe the 2 classes of receptor

Answer 46

``` 1. The first and largest class rely on cell-surface receptors to relay their message across the plasma membrane. ``` 2. The second class are generally small and hydrophobic molecules that can diffuse through the membrane. Once inside they usually bind to intracellular receptors.

Question 47

What regulates the activity of specific intracellular proteins ?

Answer 47

Nitric oxide

Question 48

Many key intracellular signaling proteins behave as __________?

Answer 48

Molecular switches

Question 49

Describe and draw protein phosphorylation and signalling by GTP

Answer 49

Found on block 1 L5 slide 7

Question 50

What are the 3 families of cell-surface receptors ?

Answer 50

Ion-channel coupled receptors,G-protein-coupled receptors, enzyme-coupled receptors

Question 51

What are ion-channel-coupled receptors responsible for and what do they do ?

Answer 51

They are responsible for the rapid transmission of signals across synapses in the nervous system and they convert chemical signals into electrical ones

Question 52

Read Block 1 L5 silde 9-15

Answer 52

DONE ?