Biol 1210: Water and Life & Carbon and molecular diversity of life

Chp 3 - Water and Life; Chp 4 - Carbon and molecular diversity of life

Define water

Molecule that supports life on earth and biological medium of earth and is the most requires substance by all organisms

What is the structure of a water molecule?

• Contains Hydrogen and Oxygen

  • Polar molecule since it has uneven charges

In general, what does the polarity of water molecule allow them do? why is this important?

• Forms hydrogen bonds with each other

  • Contributes to various properties water exhibits

What is the maximum amount of hydrogen bonds can a water molecule form?

4 Hydrogen Bonds

In general, What are the 6 properties of water based on Hydrogen Bonding?

1. Cohesive

2. Adhesive

3. Surface Tension

4. High specific heat

5. High heat of vaporization

6. Excellent solvent

What does it mean when water is cohesive?

• It is one of the properties of water based on hydrogen bonding

• It refers to the joining of many water molecules due to hydrogen bonding

What does the cohesive water property aid in?

Aids in giving water structural organization

What is the benefit of cohesiveness of a water molecule?

This property helps to pull water up through the water-conducting cells of plants called tracheid and vessel elements of the xylem tissue

What does it mean when water is adhesive?

• It is one of the properties of water based on hydrogen bonding

• It refers tot he clinging of one substance to another substance

How does water cling onto another substance?

Water can form hydrogen bonds with other molecules

What is the benefit of the water property based on hydrogen bonding; adhesion?

This property helps to pull water up through the water-conducting cells of plants as it clings to the cell wall of plants

What does it mean when water has surface tension?

• It is one of the properties of water based on hydrogen bonding

• Measure of how hard it is to break the surface of a liquid

True or False: Surface tension property of water DOES NOT relates to cohesion

False, it does

What is the benefit of the water property due to its hydrogen bonding; surface tension?

Due to it’s surface tension it causes densely packed surface layer is strong enough to support the weight of small, lightweight insects. Insects have water striders which in turn helps in them to move across the water surface

What does it mean when water has high specific heat?

• It is one of the properties of water based on hydrogen bonding

• Water can absorb or lose large amounts of heat before its own temperature is changed which is due to its hydrogen bonding

True or False: High specific heat property of water mean water CANNOT moderate air temperature

False: it can

In general, what does high specific heat mean?

Amount of heat absorbed or lost when 1g of a substance changes it’s temperature by 1°C

What is the benefit of the water property due to its hydrogen bonding; high specific heat?

Provides stable water temperature which is beneficial for aquatic organisms

In general, what does high heat of vaporization mean?

Amount of energy required to change 1g of it from liquid to gas

How does high heat of vaporization relate to water property due to it’s hydron bonding?

What is the benefit of the water property due to its hydrogen bonding; high heat of vaporization?

• Helps moderate earth’s climate (HOW)

• Help moderate an organism’s body temperature

What does it mean when water is an excellent solvent?

• It is one of the properties of water based on hydrogen bonding

• Water works as a excellent solvent since any charged or polar molecule can dissolve in water

Define solvent

Dissolving agent

Define solute

What is being dissolved

How is water molecule versatile in terms of it being an excellent solvent?

Due to its polarity

Example of Water being a solvent

• NaCl in a beaker of water which results in salt dissolving in water

• Water can transport molecules in blood

• It interacts with proteins since it has polar molecules

What is the benefit of the water property due to its hydrogen bonding; excellent solvent?

Allows many important molecules to be dissolved in it and carried to other places

Define hydrophillic

Substances that CAN bond with water due to its being ionic or polar

Define Hydrophobic and give example

• Substances that CANNOT bond with water due to it being non-ionic or polar

• Ex: Veg oil

Define Acid

Substance that increases the amount of Hydrogen Ion concentration of a solution

Example of an acid

HCl is an acid. Thus when added to water:
HCl → H⁺ + Cl^-

Define Base

Substance that decreases Hydrogen ion concentration of a solution

Example of a Base

NH₃ acts as a base.

• NH₃ +H⁺ ⇌ NH₄⁺

In pure water at 25°C, how many H⁺ is present?

1.0×10^-7M

What determine the H⁺ concentration?

pH scale or pH of a solution

What is the range of the pH scale?

0-14 with 0 being the most acidic and 14 the most basic

If pH decreases, then…

Hydrogen ion concentration increases

If pH increases, then…

Hydrogen ion concentration decreases

What is the pH formula or equation?

pH = -log[H⁺]I

If pH is less than 7, then is the solution acidic or basic?

AcidicI

If pH is more than 7, then is the solution acidic or basic?

Basic

True or False: All living organisms do not have Carbon

False, all living organisms do have carbon

What makes compounds organic?

When compounds contain carbon

Why is carbon considered important?

Considered important for its interactions with other atoms

What kind of molecules can carbon form?

Large, complex and diverse

What makes carbon special?

Carbon has an atomic number of 6. Thus, it valence 4 allows it form 4 covalent bonds with variety of atoms

Carbon can also form covalent bonds with itself, thus how do the molecules differ by?

• Length

• Branching

• Location of double bonds

• Rings

What is the simplest organic molecule?

Hydrocarbon

Define Hydrocarbon

Molecule made up of only Carbon and Hydrogen

Give examples of Hydrocarbon?

• Methane

• Ethane

• Ethene

True or False: Hydrocarbon is NOT soluble in water

True, its not {WHY}

Define Chemical groups

These groups give each molecule it unique function

Define functional groups

Chemical groups that may determine how the molecule participates in chemical reactions

List the 7 chemical groups that are most important in biological processes.

1. Hydroxyl Group

2. Carbonyl Group

3. Amino Group

4. Carboxyl Group

5. Sulfhydryl Group

6. Phosphate Group

What is the structure of the Hydroxyl Group?

What is the structure of the Carbonyl Group?

What is the structure of Amino group?

What is the structure of Carboxyl Group?

What is the structure of Sulfhydryl Group?

What is the structure of Phosphate Group?

What is structure of Methyl Group?