Biochemistry: Chemistry 101 and Properties of Water

Biochemistry: Chemistry 101

Poll

On a Scale of 1-10, how familiar are you with the term Chemistry?

• 1-3: I don't know what that word means :(

• 4-6: I kinda do know that word :l

• 7-9: Oh, I know this word :)

• 10: I know this word so well that I don't need to look it up! :D

What is Chemistry?

The study of the properties and behavior of matter, and how it interacts and
changes

Matter: Anything that has mass and takes up space. Made of elements.

Property: Any recognizable characteristic of matter.

Elements: The basic substances that make up everything. (118 currently known)

Atoms: The building blocks of matter.

Molecules: Two or more atoms together.

Multiple Choice

The building blocks of most living things contain the element

• carbon

• nitrogen

• calcium

• sodium

Multiple Choice

What is the smallest 'building block' of the elements that make up the universe?

• An atom

• An electron

• A proton

• A cell

​Electrons (e-) have a negative charge

Protons (p) have a positive charge

Neutrons do not have a charge​

​

Multiple Choice

What are the three components of an atom?

• Proton, neutron, electron

• Particle, neutron, electron

• Proton, neutron, electricity

• Proton, mitochondria, electron

The whole number, usually located in a corner is the atomic number. It represents the number of protons​

The other number, usually followed by several places beyond the decimal, is the atomic mass.​

Basic information from the periodic table:​

Reading the Periodic Table

Multiple Choice

The number of protons in the nucleus of an atom?

• Isotope

• Atomic mass

• Atomic number

• Element

Multiple Choice

What type of bond is formed when atoms share electrons?

• Covalent

• Ionic

• Hydrogen

• Polyatomic

Multiple Choice

When is an ionic bond formed?

• when electrons are shared

• when protons are shared

• when oppositely charged atoms gain or lose electrons

• when oppositely charged atoms gain or lose a proton

Multiple Choice

How are ionic and covalent bonds alike?

• They both form organic molecules.

• They both fill outer electron shells.

• They both transfer electrons from one atom to another.

• They both transfer protons from one atom to another.

In a hydrogen bond, the partially positive and partially negative poles of an atom are attracted to each other like a magnet.​ These bonds include a hydrogen

​

Hydrogen Bond

​

These bonds are between a negatively charged and positively charged pole. This is the weakest charge.​

​

​van der Waals

​

Multiple Choice

Which is the weakest bond?

• Ionic

• Covalent

• Hydrogen

• van der Waals

Multiple Choice

What makes a chemical reaction?

• matter is conserved

• breaking and forming of chemical bonds

• when products form reactants

• when you do a lab

Explanation Slide...

Cohesion is where water molecules stick together because of hydrogen bonding.

Multiple Choice

The tendency of molecules of the same kind to stick to one another is called .....

• cohesion
• adhesion
• solution
• polar molecule

Multiple Choice

Attractions between water molecules are called ....

• Covalent bonds

• Ionic bonds

• Polar bonds

• Hydrogen bonds

Explanation Slide...

Surface tension is where the force of the hydrogen bonds push up supporting the weight of the paper clip. As soon as the hydrogen bonds are broken, the paperclip will sink.

Multiple Choice

Which characteristic of water will allow a paperclip to remain floating on the surface of water?

• adhesion

• surface tension

• solvent properties

• non-polar

Multiple Choice

The meniscus in a graduated cylinder or glass of water is due to.....

• The water molecules being attracted to the glass and adhering to it

• The water molecules being attracted to the glass and cohering to it

• The water molecules being non-polar and repelling the glass

• Because water is hydrophilic

Multiple Choice

A water strider can skate along the top of a pond because....

• covalent bonds result in water cohesion (surface tension)

• hydrogen bonds result in water cohesion (surface tension)

• water striders have adapted to become lighter than water

• low surface tension of water

Explanation Slide...

A solvent is a liquid that allows other substances to dissolve into it. Remember, most chemical reactions happen in solution (dissolved in a liquid).

Multiple Choice

Water is a universal solvent because...

• it can be found anywhere

• it freezes when it gets cold

• it floats when frozen

• it dissolves most substances

Specific Heat

• So why does it take water So long to heat up?

• As you can see its more than just putting the pot on the stove...

Multiple Choice

Why does ice float?

• As water freezes, it expands and its density decreases.
• As water freezes, it takes up more hydrogen from the atmosphere, causing it to have a greater buoyancy.
• As water freezes, air becomes trapped between the hydrogen bonds of water molecules.
• As water freezes, it takes up more oxygen from the atmosphere, causing it to have a greater buoyancy.

Multiple Choice

Large bodies of water, such as lakes and oceans, do not quickly fluctuate in temperature. What is the reason for this phenomenon?

• Water is an acid.
• Water is a versatile solvent.
• Water has a high heat capacity.
•  Water acts as a buffer.

pH Scale

11 - 14 = Strong

8 - 10 = Weak

Bases

0 - 3 = Strong

4 - 6 = Weak

Acids

pH = strength of acids/bases

Scale from 0 - 14

Ion Concentration

As the pH level changes, so does the concentration of ions

Hydronium (H₃O+) Ions ----- greater concentration in acids
Hydrogen (H+) Ions --------- greater concentration in acids
Hydroxide (OH-) Ions ------- greater concentration in bases

Indicators

Substance that changes color to
show pH level.
*Liquids and Solids


Examples
Litmus Paper - Blue = Base, Red = Acid
pH Paper - Scale of 0-14
Universal Indicator Solution - 0-14

Poll

How would acidification of seawater affect marine organisms?

• It will increase dissolved carbonate concentrations and promote faster growth of corals and shell-building animals.

• It will decrease dissolved carbonate concentrations and promote faster growth of corals and shell-building animals.

• It will increase dissolved carbonate concentrations and hinder growth of corals and shell-building animals.

• It will decrease dissolved carbonate concentrations and hinder growth of corals and shell-building animals.