Unit 1 Flashcards

Flashcards based on lecture notes for Unit 1, covering water properties, pH, CHNOPS, monomers, polymers, and macromolecules.

Why is water considered a polar molecule?

Due to unequal electron sharing, resulting in partial positive charges on hydrogen atoms and a partial negative charge on the oxygen atom.

What type of bonds are essential in the structure of nucleic acids and proteins, though they are weak individually?

Hydrogen bonds

What properties of water are attributed to cohesion (hydrogen bonds between water molecules)?

High heat of vaporization, high specific heat, and high surface tension.

Define adhesion in the context of water.

Water sticking to other substances.

What is transpiration?

Water's ability to cohere to other molecules, such as the sides of a plant.

How is surface tension defined?

The force exerted by water molecules on a body of water.

What characterizes an acidic solution in terms of hydrogen ions?

More hydrogen ions (H+) than hydroxide ions (OH-), with a pH less than 7.

What characterizes a basic solution in terms of hydroxide ions?

More hydroxide ions (OH-) than hydrogen ions (H+), with a pH greater than 7.

What does CHNOPS stand for?

Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulfur - the most important chemical elements in biological molecules.

Why is carbon considered a central element in biological molecules?

Its ability to form stable bonds with many other elements and itself.

What role does hydrogen play in energy exchange?

Important role particularly in ATP/cellular respiration.

What are monomers?

Small building blocks that are used to build polymers.

How are polymers formed from monomers (general process)?

Through dehydration synthesis, where water is removed to create a bond between monomers.

What is hydrolysis?

An enzyme inserts a water molecule between two monomers, breaking them apart.

Give an example of a disaccharide, and describe it.

Carbohydrates (two linked monosaccharides) which are energy transfers.

Give examples of Macromolecules

Phospholipids-lipids, Hemoglobin-proteins, DNA-Nucleic Acids

What role do monosaccharides play?

Energy source and building blocks.

What roles do polysaccharides play?

Energy storage and structural roles, such as in cell walls.