Water

Question 1

What is Water used For

Answer 1

Water is the medium in which most processes of life occur.

Question 2

Hydrogen Bonding

Answer 2

The attraction between slightly positive and slightly negative regions of two different polar molecules.

Question 3

Hydrogen Bond Weakness

Answer 3

Hydrogen Bonds are weak and can be broken easily, however, due to water having a large amount of hydrogen bonds it contributes to its stability and strength.

Question 4

Properties of Water

Answer 4

Cohesive Properties: Can stick to each other.

Adhesive Properties: Can stick to surfaces.

Solvent Properties: Can dissolve hydrophilic molecules easily.

Thermal Properties: Hydrogen bonds require a large amount of heat energy to break.

Question 5

Significance of Cohesion

Answer 5

Cohesion is important for water to move up xylem vessels in plants.

Cohesion creates surface tension which allows some insects to move on water’s surface.

Question 5

Significance of Adhesion

Answer 5

Water is attracted to the cellulose cell wall of the xylem and sticks to it to rise against gravity.

Helps bring water upwards from the soil into the roots.

Question 6

Significance of Solvent

Answer 6

Water acts as a medium for all metabolic reactions in the cytoplasm.

Water acts as a transport medium in plants and animals.

Question 7

Significant of Thermal

Answer 7

Cells can withstand a lot of heat energy release from their metabolic reactions without boiling away.

Question 8

Molecules that are Polar or Non-Polar

Answer 8

Glucose: Polar

Amino Acids: Depending on R group

Oxygen: Non-Polar

NaCl: Ionic

Fats: Non-Polar

Question 9

Solubility of Molecules

Answer 9

Glucose: Soluble

Amino Acids: Depending on R group

Oxygen: Soluble due to small size

NaCl: Soluble

Fats: Insoluble

Question 10

Mode of Transport for Molecules

Answer 10

Glucose: Dissolved in blood plasma

Amino Acids: Dissolved in blood plasma

Oxygen: Attaches to the hemoglobin of the RBC

NaCl: Ionizes into Na and Cl in plasma

Fats: Carried in blood plasma inside lipoprotein complexes with a single layer of phospholipids

Question 11

Physical Properties of Water

Answer 11

Buoyancy: An upward force exerted by a fluid on an object. (Depends on density of object)

Viscosity: Resistance to flow (Solutes can increase viscosity)

Thermal Conductivity: Ability of water to pass heat (Increases up util boiling point)

Specific Heat Capacity: The amount of energy it takes to increase the temperature of 1g of water by 1C

Question 12

Water Physical Properties Consequences on Organisms

Answer 12

Buoyancy: Helps organisms use water as their habitat as they can float without using energy

Viscosity: High viscosity can make it more challenging for aquatic animals to swim efficiently

Thermal Conductivity: Allows warm-blooded animals to have insulating properties and remove excess heat

Specific Heat Capacity: Helps organisms use water as their habitat as water doesn’t change as easily as air does

Question 13

Extraplanetary Origin of Water on Earth

Answer 13

Two 4.5 billion year old meteorites found on earth contained a liquid that is similar to the ocean water. This suggests that the water in these meteorites are the source of Earth’s oceans.

Evidence: Earth’s current deuterium to hydrogen ratio also matches Earth’s seawater.

Question 14

Reasons for Retention of Water on Earth

Answer 14

Earth’s distance from the Sun ensures that the temperature will never be high enough for water to boil which makes water get retained much more easily.

When meteorites heat up, they cool down once they come to earth and condense their water vapor into liquid water.

Earth has strong gravity which holds oceans tightly to its surface and holds gases in the atmosphere.

Question 15

Goldilocks Zone and Water

Answer 15

Water is the source of life, therefore planets need to be in a specific distance away from the sun in order to have water.

This zone is called “The Goldilocks Zone”.

If a planet is too close, water will vaporize. If a planet is too far, water will freeze.

Question 16

Location of Goldilocks Zone

Answer 16

The location of the Goldilocks Zone depends on:

The size of the star and amount of energy it emits

The size of the planet which determines strength of gravity and atmospheric pressure

The more planets there are in the Goldilocks Zone, the higher chance there is for extraterrestrial life to exist.

Question 17

Importance of Hydrogen Bonding in Water

Answer 17

Cohesion in water helps transport water in the xylem.

Adhesion between water and cell walls helps defy gravity to travel up xylem.

Thermal property is as much energy is required to break the hydrogen bond.

Solvent property of water with hydrophilic molecules.

Question 18

Buoyancy of Gavia Artica in Air and Water

Answer 18

Air: Has hollow bones to decrease weight so it can fly easily in the air

Water: Can dive long deep distances underwater by compressing air from lungs and feathers to decrease buoyancy

Question 19

Buoyancy of Pusa Hispida in Air and Water

Answer 19

Has thick layer of fat under the skin (blubber) which provides low density and increases buoyancy

Question 20

Viscosity of Gavia Artica in Air and Water

Answer 20

Air: Gavia Artica can easily move through the air when flying since air is not viscous

Water: Has webbed feet to provide large surface area to push against water, and has a streamlined body shape to reduce drag in water

Question 21

Viscosity of Pusa Hispida in Air and Water

Answer 21

Air: High viscosity of water at cold temperatures allows them to create and maintain breathing holes

Water: Bodies are adapted for swimming through the water

Question 22

Thermal Conductivity of Gavia Artica in Air and Water

Answer 22

Air: They can trap air in their feathers forming an insulating layer which reduces heat loss

Water: Their feathers contain oil glands that release oil which provides a hydrophobic barrier which insulates the body from heat loss

Question 23

Thermal Conductivity of Pusa Hispida in Air and Water

Answer 23

Blubber helps insulate the body

The air trapped in their fur and blubber serves as an insulator which keeps them warm and conserve body heat

Question 24

Specific Heat Capacity of Both Animals

Answer 24

Helps both mammals maintain a stable body temperature because the temperature of water doesn’t change as fast as air

Water is warmer than air in colder temperatures which allows for both mammals to spend more time in water