Biological Molecules and Reactions

This video tutorial covers key biochemistry topics, including the properties of water, the pH scale, macromolecules, and enzymes. It explains water's unique properties, the significance of the pH scale, the structure and function of macromolecules, and how enzymes act as catalysts in chemical reactions.

What is the chemical formula of water?

• H2O

• O2

• CO2

• H2

Why does ice float on water?

• Ice is denser than water

• Ice is less dense than water

• Ice has a higher boiling point

• Ice is nonpolar

What property of water allows it to dissolve many substances?

• Its low boiling point

• Its polarity

• Its high density

• Its nonpolar nature

What is the pH of a neutral substance?

• 0

• 7

• 14

• 10

Which macromolecule is primarily used for quick energy in living organisms?

• Proteins

• Lipids

• Carbohydrates

• Nucleic acids

What is the monomer of proteins?

• Nucleotides

• Amino acids

• Fatty acids

• Monosaccharides

What role do enzymes play in biological reactions?

• They are used up in reactions

• They act as reactants

• They slow down reactions

• They speed up reactions

What is the specific part of an enzyme where the substrate binds?

• Binding site

• Active site

• Reaction site

• Catalytic site

How do enzymes affect activation energy?

• They have no effect

• They decrease it

• They increase it

• They eliminate it

What is the term for a reaction without an enzyme?

• Deactivated

• Activated

• Catalyzed

• Uncatalyzed