Lecture 1 Biological molecules

Question 1

What are the types of chemical bonds?

Covalent bond

Answer 1

covalent bonds - share a pair of electrons between two atoms

Question 2

What is an ionic bond?

Answer 2

is an electrostatic attraction bwtween full positive and negative charges on ions

Question 3

What are van der waals interactions?

Answer 3

interactions between partial positive and partial negative regions of different molecules

Question 4

What is a hydrogen bond?

Answer 4

can be formed when hydrogen atom that is covalently bonded to a highly electronegative atom (O2, N) is partially stripped of its electrons by that atom, allowing a transient bond to form with a highly electronegative atom on a nearby molecule

Question 5

chemical reactions consist of what?

Answer 5

breaking of some bonds between atoms and the formation of others

without the lose of materisal

Question 6

Breaking bonds requires what?

Answer 6

energy

Question 7

The formation of new bonds does what?

Answer 7

releases energy

Question 8

Water molecules are what?

Answer 8

uncharged and polar and can form hydrogen bonds with other water molecules

Question 9

What explains waters unusual behaviour?

Answer 9

uncharged, polar, can form hydrogen bonds with other water molecules

Question 10

Why are water molecules cohesive?

Answer 10

due to their hydrogen bonds

Question 11

water has a high heat capacity due to what?

Answer 11

hydrogen bonds

Question 12

water has a high boliling point due to what?

Answer 12

hydrogen bonds

Question 13

Water molecules will associate with what?

Answer 13

other uncharged molecules that have polar covalent bonds and with the full charges on ions

Question 14

Hydrogen bonds in ice and water

Answer 14

In water the hydrogen bonds form and break constantly

In ice the hydrogen bonds are stable due to lower thermal energy

Question 15

If a molecule cannot be superimposed on its mirror image it is what?

Answer 15

is said to have chiral properties

Question 16

An organic molecule is chiral if it has what?

Answer 16

At least one carbon atom bonded to four different groups (an asymmetric carbon). the two mirror image fors are called enantiomers

Question 17

What areenantiomers

Answer 17

two mirror image forms

Question 18

Most molecules in cells are what?

Answer 18

chiral

Question 19

Organic molecules are molecules containing what?

Answer 19

carbon

Question 20

since carbon atoms can for covalent bonds there is what?

Answer 20

a huge variety of carbon skeleton possibilities

Question 21

Much of the reactivity and functionality of organic molecules in cells arise from what?

Answer 21

from the functional groups they contain