Biology chapter 5 The Structure and Function of Large Biological Molecules

What are the large biological molecules built from similar building blocks?

They are polymers, which include large carbohydrates (polysaccharides), proteins, and nucleic acids. Lipids are an exception as they do not include true polymers.

What are the building blocks of polymers called?

They are called monomers.

What is the reaction that links monomers together, and what is the molecule lost?

A dehydration reaction, which bonds monomers through the loss of a water molecule.

What is the reverse reaction that disassembles polymers?

Hydrolysis, which adds a water molecule to break a bond.

List the four main categories of large biological molecules.

Carbohydrates, Lipids, Proteins, and Nucleic acids.

What are the two major functions of carbohydrates?

They serve as fuel (energy source) and building material.

Name the monomer of a carbohydrate.

A monosaccharide, or simple sugar, such as glucose. What is the structural difference between starch and cellulose, despite both being made of glucose?

What is the function of Starch in plants and Glycogen in animals?

Starch stores glucose for energy in plants. Glycogen stores glucose for energy in animals, mainly in liver and muscle cells. What is the function of Cellulose?

Why are lipids not considered true polymers?

Lipids are the one class of large biological molecules that does not include true polymers.

What is the defining characteristic of lipids?

They are hydrophobic (they mix poorly, if at all, with water). What are the three main components of a triacylglycerol (fat or oil)?

What is the major function of fats?

They are an important energy source and adipose tissue also cushions vital organs and insulates the body.

What is the structural difference between saturated and unsaturated fatty acids?

Saturated fatty acids have the maximum number of hydrogen atoms possible and no double bonds. Unsaturated fatty acids have one or more double bonds.

How are phospholipids structured, and what is their main function?

They are constructed from glycerol, a phosphate group, and two fatty acids. They form lipid bilayers of membranes, which are the boundary between the cell and its external environment.

What defines the structure of a steroid, and what are their functions?

Steroids are lipids characterized by a carbon skeleton of four fused rings. They function as a component of cell membranes (cholesterol) and as signaling molecules (hormones).

What is the monomer of a protein, and how many types are used to build proteins?

The monomer is an amino acid, and proteins are constructed from the same set of 20 amino acids.

What part of the amino acid determines its specific properties?

The differing side chains, called R groups.

List three major functions of proteins.

They catalyze chemical reactions (enzymes), transport substances (e.g., hemoglobin), and provide structural support (e.g., collagen).

What determines a protein's function?

Its specific activities result from its intricate three-dimensional architecture. Function usually depends on its ability to recognize and bind to some other molecule.

What are the four levels of protein structure?

Primary structure (amino acid sequence), Secondary structure (coils and folds like α helix and β pleated sheet), Tertiary structure (R group interactions), and Quaternary structure (multiple polypeptide chains).

What is the monomer of a nucleic acid, and what are its three parts?

The monomer is a nucleotide. Its three parts are a nitrogenous base, a pentose sugar, and one or more phosphate groups.

What are the two types of nucleic acids?

Deoxyribonucleic acid (DNA) and Ribonucleic acid (RNA).

What are the two major differences in components between DNA and RNA?

DNA has the sugar deoxyribose and uses the base Thymine (T). RNA has the sugar ribose and uses the base Uracil (U). What is the structure of DNA, and how is it held together?

What are the main functions of DNA and RNA?

DNA stores hereditary information and provides directions for its own replication. RNA has various functions in gene expression, including carrying instructions from DNA to ribosomes for protein synthesis.

Define Genomics and Proteomics.

Genomics is an approach that analyzes large sets of genes or whole genomes. Proteomics is a similar approach that analyzes large sets of proteins, including their sequences.

What is the role of Bioinformatics?

It is the use of computational tools and computer software to analyze large data sets generated from sequencing many genomes and proteins.

How do DNA sequences act as "tape measures of evolution"?

The more closely two species are related evolutionarily, the more similar their DNA sequences are. These sequences document the hereditary background of an organism and confirm evolutionary models.