Quiz on Bonds, Water, pH, carbon, molecular diversity

Basic chem (esp. bonds), Water structure, bonds involved, Properties of water: what they are and why they are important to life, Acids and Bases, pH and pH scale, Carbon and molecular diversity, Isomers, Functional groups

Hydroxyl

Polar

Found in SUGARS

Methyl

Nonpolar

Hydrophobic

“Turns genes off”

Includes fatty acids, oils, waxes (all lipids)

Carbonyl

Polar, Hydrophilic

Carboxyl

Charged, ionizes to release H⁺

Polar, Weak Acid, Hydrophilic

Ex) Amino acids and Fatty Acids

Amino

Charged, ionizes to accept H⁺ to form NH₃⁺

Polar

Hydrophilic

Phosphate

Charged, ionizes to release H⁺

Polar, Acid, Hydrophilic, negative

Important in energy transfer

ex) Nucleotides, phospholipids, ATP

Sulfhydryl

Form disulfide bridges

Help stabilize tertiary structure of proteins

Structural Isomers

Differ in arrangement of atoms

Geometric Isomers

Differing structurally only with the placement of groups around the double bond (esp. seen w/ C=C)

Enantiomers

Mirror images of one another, occurs w/ asymmetric carbon

What is an Isomer?

Molecules with the same molecular formula but different structures/shapes.

These different shapes leads to different chemical and biological properties.

What does pH measure?

Concentration of H⁺ ions

What happens if you go up on the pH scale?

Concentration of H⁺ ions goes DOWN

Concentration of OH^- goes UP

What is the concentration of both H⁺ and OH^- at pH 5?

[H⁺] = 1.0 × 10^-5

[OH^-] = 1.0 × 10^-9

What are solutions from 0-7?

What are solutions from 0-14?

0-7 are acids

7-14 are bases

How much more concentrated is pH 7 compared to pH 10?

1 × 10³ = 1000

Covalent Bonds, polar vs nonpolar

Share electrons, Intramolecular, STRONG

Polar —> unequal sharing of electrons

non-polar —> equal sharing of electrons

Ionic Bonds

Forms between ions of opposite charges, Intramolecular, STRONG

Hydrogen Bonds

Forms between Hydrogen of one molecule and F,O,N of another

Intermolecular, weak

Cohesion of water

water molecules stick to each other (w/ H-Bonds)

Adhesion of water

Water molecules sticks to surfaces

Why is cohesion/adhesion important in water?

Capillarity - Allows for water to move against gravity, good for transport of water in plants

Surface Tension in Water

H₂O molecules at the surface are more strongly attracted to each other, allows for insects to walk on water

Water is a Good Solvent

H₂O dissolves many polar/charged substances, they are called hydrophilic substances. Hydrophobic, non-polar won’t dissolve

Allows for chemical reactions to happen in cells/bodies

Ice floats (less dense than water)

Water expands when it freezes. Allows for bodies of water to freeze from the top down, acts as an insulator for aquatic ecosystems

High Heat Capacity of Water

Resists temperature changes

Heat absorb breaks H-Bonds without changing its temperature

Allows for stable temperature in our body and aquatic ecosystems.

High Heat needed to Vaporize

Water needs lots of energy/heat in order to vaporize. When water evaporates, energy is taken up by the process, cooling the place where it takes place. The Evap of sweat cools us.
As sweat evaporates, it absorbs heat/energy from the body, which cools it.

What are Buffers?

Buffers absorb excess H⁺ or OH^–, keeping the pH of the body within its range.

ex) in blood - bicarbonate