Week 4 (1) Flashcards Preview

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Flashcards in Week 4 (1) Deck (24)
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1
Q

What is covalent bonding?

A

A covalent bond arises from a shared pair of electrons

2
Q

How many covalent bonds are formed by:

H

C

N

O

F

A

1

4

3

2

1

3
Q

What charged ion does Zn tend to form?

A

Zn 2+

4
Q

What charged ions does Ni tend to form?

A

Ni 2+

5
Q

What charged ions does Mn tend to form?

A

Mn 2+ Mn 3+ Mn 7+

6
Q

What charged ions does Fe tend to form?

A

Fe 2+

Fe 3+

7
Q

What charged ions does cobalt tend to form?

A

Co 2+ Co 3+

8
Q

What charged ions doe copper tend to form?

A

Cu+

Cu 2+

9
Q

What charged ion does Cd tend to form?

A

Cd 2+

10
Q

What charged ion does Hg tend to form?

A

Hg 2+

11
Q

What charged ion does Al tend to form?

A

Al 3+

12
Q

How can structure affect the strength of a hydrogen bond?

A

Electronegative atom with a hydrogen attached close to another electronegative atom preferably all in a straight line (bond angle of 180 degrees) will make the hydrogen bond stronger

13
Q

What do Van der Waals Forces involve? Are they stronger/ weaker than hydrogen bonds?

A
  • Weak bonds which exist between all molecules
  • electrons are constantly moving which causes involves instantaneous dipoles that induce dipoles in neighbouring molecules
  • Weaker than hydrogen bonds
14
Q

Van der Waals : What causes uneven distributions of the electronic charge (polarity)?

A

Oscillations of electrons cause transient, uneven distributions of the electronic charge (polarity)

15
Q

Van der Waals: what makes these attractions stronger?

A

When molecules have large surface areas that can come into close contact, the total attraction from such interactions can be VERY LARGE.

16
Q

What compound is Van der Waals important for?

A

The 3D shape of a protein molecule is essential for its correct functioning, and Van der Waals forces are important in maintaining this shape.

17
Q

Water has an ordered structure because of

A

hydrogen bonding

18
Q

What happens to hydrogen bonds when a solute is dissolved in it?

A

involves breaking these hydrogen bonds – costs energy

19
Q

What property allows for interactions with an aqueous medium?

A

The more polar, hydrophilic side chains tend to be on the surface

20
Q

What do Hydrophobic portions of bio-molecules tend to associate with?

A

-each other because they “cannot pay the energy cost.” - Hydrophobic amino acid side-chains in globular proteins tend to associate with the hydrophobic core.

21
Q

What do polar compounds usually have?

A

usually contain electronegative atoms, hydrogen bonding groups or charged groups.

22
Q

What do non polar compounds usually lack?

A

usually deficient in electronegative atoms, hydrogen bonding groups or charged groups.

23
Q

Name 6 key points about bonding in biological compounds?

A
  1. A covalent bond arises from the SHARING of a PAIR of electrons.
  2. Hydrogen bonding arises from a polarisation of covalent bonds by electronegative atoms.
  3. Hydrogen bonds are MUCH WEAKER than covalent bonds.
  4. Ionic bonding results from the transfer of an electron or electrons from one atom to another.
  5. Hydrophobic portions of bio-molecules tend to associate with each other because they cannot pay the energy cost of breaking the hydrogen bonding present in water.
  6. Van der Waals forces are weak, transient but very important in large molecules.
24
Q

Classify these compounds into polar and non-polar comppounds

A