Biological Molecules: Water

Question 1

Name the 4 different types of specimen sampling/ viewing

Answer 1

1) Dry mount
2) Wet mount
3) Squash slides
4) Smear slides

Question 2

The 2 steps to dry mount

Answer 2

1) The specimen is viewed either whole or cut - Sectioning

2) Place a cover slip over the sample

Question 3

The 2 steps to wet mount

Answer 3

1) Specimens are suspended in liquid

2) A cover slip is placenta an angle over the sample

Question 4

The 3 steps to squash slides

Answer 4

1) A wet mount is prepared
3) A lense tissue is gently pressed down over the cover slip
4) Don’t break the cover slip

Question 5

What precautions can be taken to prevent damage to a cover slip?

Answer 5

Squash the sample in-between two slides

Question 6

The 3 steps to smear slides

Answer 6

1) The edge of a slide is used to wear the sample thinly and evenly

Question 7

Hydrogen Bond

The electrostatic attraction between a slightly ___1____ hydrogen atom of one water molecule and the slightly ____2____ oxygen atom of another water molecule produces ____3____

Answer 7

1) Positive
2) Negative
3) Hydrogen bond

Question 8

What does oxygen do with the shared electrons and why?

Answer 8

Drags the shared electrons closer to it because it has bigger nucleus. (A greedy git)

Question 9

What bond is between the oxygen and hydrogen atoms?

Answer 9

Covalent

Question 10

What bond is between each of the water molecules?

Answer 10

Electrostatic bond

Question 11

A water molecule is a what?

Answer 11

Dipole

Question 12

Dipole is where…

Answer 12

Electrons are pulled to the the oxygen, creating a slightly positively charged hydrogen end and a slightly negatively charged oxygen side.

Question 13

What is the difference polar and non-polar molecules?

Answer 13

Polar molecules have an unbalanced charge so slightly positive or negative whereas non-polar molecules are equally charged.

Question 14

Cohesion…

Answer 14

Where water molecules bond to each other.

Question 15

Adhesion…

Answer 15

Is between a water molecule bonding with a different molecule.

Question 16

When the adhesion is stronger than the cohesion bonds a ______ is formed.

Answer 16

Meniscus

Question 17

What is formed by cohesion bonds in water?

Answer 17

Surface tension

Question 18

How does surface tension help organisms to live?

Answer 18

Pond skaters us this to move across water to feed.

Question 19

What is the importance of cohesion and adhesion?

Answer 19

It results in capillary action allowing liquids to move up the xylem.

Question 20

What is meant by high specific heat capacity?

Answer 20

It is the measure of kinetic energy of water molecules. These are held together by strong hydrogen bonds thus a lot of energy is needed to break these bonds.

Question 21

What is the importance of high specific heat capacity in the survival of organisms.

Answer 21

1) It creates a thermally stable environment. Rising temperatures reduces oxygen levels.
2) Provides a stable internal temperature inside organisms allowing enzymes to work.

Question 22

What is the importance in high latent heat of evaporation in living organisms. (Heat needed for evaporation)

Answer 22

Water acts as a coolant when evaporating. It maintains a stable temperature inside the organism.

Question 23

What are the properties of Ice and who does it contribute to the survival of organisms.

Answer 23

• Less dense than water.
• At temperatures below 4 degrees water molecules align themselves in a crystalline structure that is less dense.
• It insulates the water below reducing rate of heat loss.
• Creates a stable environment.

Question 24

Water as a Solvent.

Answer 24

• Water is dipole acting as a solvent for the ionic molecules.
• Water molecules are attracted to the charged part of the solute. They surround it and separate them from the rest.
• Cytoplasm is over 70% water it allows molecules to move and react.
• Allows for transportation of molecules e.g. bloodstream or xylem.