Bio Unit 1 Test Review

What are the Polar molecules?

O, S, P, & N

What elements make up carbohydrates?

C, H, O (CH₂O)

What elements make up lipids?

C, H, O

What elements make up proteins?

C, H, O, N (SOMETIMES S)

What elements make up nucleic acids?

C, H, O, N, P

What is the monomer for carbohydrates?

Monosaccharides

What is the monomer for lipids?

Fatty acid & Glycerol

What is the monomer for proteins?

Amino Acid

What is the monomer for Nucleic Acids?

Nucleotides

A molecule contains C, H, O, N, and P and consists of a phosphate group, five-carbon sugar, and nitrogenous base. What is it?

A nucleotide

What are the three components of a nucleotide?

Phosphate group, five-carbon sugar, and nitrogenous base

What determines the specific properties of an amino acids?

The R group

What type of bond connects amino acids?

Peptide bonds

What type of bond connects monosaccharides?

Glycosidic linkages

What type of bond connects nucleotides in a nucleic acid strand?

Phosphodiester bonds

What is starch?

A glucose-based polysaccharide used for energy storage in plants

What is glycogen?

A glucose-based polysaccharide used for energy storage in animals

What is cellulose?

A structural glucose polysaccharide found in plant cell walls

Why can two polysaccharides made of glucose have different functions?

Their glucose monomers are connected differently, producing different molecular structures.

Why can humans digest starch but not cellulose?

Humans have enzymes that can hydrolyze starch's linkages but lack the enzymes needed to hydrolyze cellulose's specific linkages.

A researcher changes the arrangement of glucose monomers in a polysaccharide. Why could the change affect biological function?

Changing the structure can alter the molecule's interactions with other molecules.

A molecule contains phosphorus. Does this prove that it is a nucleic acid?

No. Phospholipids can also contain phosphorus.

What is the primary biological advantage of storing energy as lipids rather than carbohydrates?

Lipids contain many energy-rich C-H bonds and store large amounts of energy in a relatively compact form.

Why do unsaturated fatty acids often have lower melting points than saturated fatty acids?

Their double bonds create bends that prevent the fatty acid chains from packing tightly.

Why is the primary structure of a protein important?

The amino acid sequence influences how the protein folds and therefore its final three-dimensional structure.

Does denaturation necessarily break peptide bonds?

No. It usually disrupts interactions responsible for higher-order protein structure.

Why can extreme pH reduce enzyme activity?

Changes in H⁺ concentration can alter the charges on amino acid side chains and disrupt interactions maintaining protein structure.

Why is water an effective solvent?

Its polarity allows it to interact with ions and polar molecules.

When the surface temperature drops below freezing a layer of ice forms on the top of the lakes and ponds.   Which of the following best describes how the structure of ice benefits organisms living below the surface of the lake or pond?

The water molecules in ice are further apart that those in liquid water, so ice floats, creating a layer of insulation keeping the water underneath the ice slightly above freezing.

Most abundant atoms in living organisms

C,H,N,O,P,S

α linkage

O is “down” Digestible by animals

β linkage

O alternates up and down NOT digestible by animals

functional group

part of a molecule that can participate in chemical reactions. 

Fatty Acids

long carbon chains (12-18 Cs) with a -COOH (acidic) on one end and a -CH₃ at the other

Glycerol

a 3-carbon sugar with three OH groups, making it easy to add fatty acids