Study Guide/Objectives for Chapter 3: Biological Molecules

What is an organic molecule?

An organic molecule contains carbon bonded to hydrogen and is found in living organisms.

How many bonds can carbon form?

Carbon can form four covalent bonds.

Why can carbon form many different molecules?

Carbon’s four bonds allow chains, rings, and complex 3D structures.

What is the significance of carbon diversity?

It allows a wide variety of molecules with different functions in living organisms.

Which functional groups are found in amino acids?

Amino acids contain an amino group and a carboxyl group.

Which functional group is important in ATP?

The phosphate group is important in ATP.

What is a polymer?

A polymer is a large molecule made of repeating monomers.

How are polymers formed?

Polymers form by dehydration synthesis, which removes water to join monomers.

How are polymers broken down?

Polymers are broken down by hydrolysis, which adds water to break bonds.

What happens during dehydration synthesis?

A water molecule is removed to form a covalent bond between monomers.

What happens during hydrolysis?

A water molecule is added to break a covalent bond between monomers.

What are the four major biomolecule groups?

Carbohydrates, lipids, proteins, and nucleic acids.

What are characteristics of carbohydrates?

Carbohydrates contain CHO in a 1

What are characteristics of lipids?

Lipids are mostly hydrophobic and made of hydrocarbons.

What are characteristics of proteins?

Proteins contain CHON and have diverse functions.

What are characteristics of nucleic acids?

Nucleic acids contain CHONP and store genetic information.

What are carbohydrate monomers?

Monosaccharides are the monomers of carbohydrates.

What are lipid subunits?

Lipids are made of glycerol and fatty acids.

What are protein monomers?

Amino acids are the monomers of proteins.

What are nucleic acid monomers?

Nucleotides are the monomers of nucleic acids.

Are carbohydrates hydrophobic or hydrophilic?

Carbohydrates are hydrophilic.

Are lipids hydrophobic or hydrophilic?

Lipids are hydrophobic.

What is the CHO ratio in monosaccharides?

Monosaccharides have a 1

What is the most important monosaccharide?

Glucose is the most biologically important monosaccharide.

How are disaccharides formed?

Disaccharides form by dehydration synthesis between two monosaccharides.

What are four important polysaccharides?

Starch, glycogen, cellulose, and chitin.

What do polysaccharides have in common?

They are polymers of glucose or similar sugars.

Why do polysaccharides differ?

They differ in structure and type of glycosidic bonds.

What characteristic groups lipids together?

Lipids are grouped by being hydrophobic.

What is a triacylglycerol?

A triacylglycerol is glycerol bonded to three fatty acids for energy storage.

What is a phospholipid?

A phospholipid has glycerol, two fatty acids, and a phosphate group and forms membranes.

What is the difference between saturated and unsaturated fats?

Saturated fats have no double bonds, while unsaturated fats have one or more double bonds.

How do saturated and unsaturated fats differ physically?

Saturated fats are solid, while unsaturated fats are liquid at room temperature.

Where are saturated vs unsaturated fats commonly found?

Saturated fats are common in animals, while unsaturated fats are common in plants.

What are some functions of proteins?

Proteins act as enzymes, structure, transport, signaling, movement, and defense.

Why can proteins perform many functions?

Proteins have diverse amino acid sequences and shapes.

What is the monomer of proteins?

The monomer of proteins is the amino acid.

What bond links amino acids?

Peptide bonds link amino acids.

What are the parts of an amino acid?

An amino acid has a central carbon, amino group, carboxyl group, hydrogen, and R group.

How do two amino acids join?

They join by dehydration synthesis forming a peptide bond.

How do R groups affect proteins?

R groups determine chemical properties and affect protein folding and function.

What are the four levels of protein structure?

Primary, secondary, tertiary, and quaternary structure.

What is primary protein structure?

It is the sequence of amino acids.

What is secondary protein structure?

It is folding into alpha helices and beta sheets via hydrogen bonds.

What is tertiary protein structure?

It is the overall 3D shape formed by R group interactions.

What bonds are involved in tertiary structure?

Hydrogen bonds, ionic bonds, disulfide bridges, and hydrophobic interactions.

What is quaternary protein structure?

It is the arrangement of multiple polypeptide chains.

What happens when a protein denatures?

It loses its shape and function.

Which protein structures are affected by denaturation?

Secondary, tertiary, and quaternary structures are disrupted.

Can a denatured protein function?

No, because its shape is necessary for function.

What causes protein denaturation?

Heat, pH changes, and chemicals can cause denaturation.

Is protein denaturation reversible?

Sometimes, but often it is not.

What are nucleic acid monomers called?

Nucleotides are the monomers of nucleic acids.