5 Molecules in Living Systems - Carbon-Based Molecules

A comprehensive set of flashcards covering carbohydrates, lipids, proteins, nucleic acids, and foundational concepts (monomers vs polymers, structures, and functions) from the lecture notes.

What is a monomer?

A molecule that can bond to identical molecules to make polymer chains.

What is a polymer?

A molecule made of repeating units (monomers).

What elements predominantly compose lipids?

Carbon and hydrogen.

What functional group is found in the polar head of phospholipids?

Phosphate group.

What is the general formula unit for carbohydrates?

(CH2O)n.

What are the three main categories of carbohydrates?

Monosaccharides, disaccharides, polysaccharides.

Give an example of a monosaccharide.

Glucose (also ribose).

Give an example of a disaccharide.

Sucrose.

Name storage polysaccharides in plants and animals.

Starch (plants) and glycogen (animals).

Which carbohydrate provides structural support in plants?

Cellulose.

What is the primary function of carbohydrates in energy production?

To generate energy through respiration (producing ATP).

What is a polysaccharide?

A carbohydrate polymer made of many monosaccharide units.

What are major and minor grooves associated with?

Nucleic acids (DNA).

What are the two main classes of nitrogenous bases?

Purines and pyrimidines.

Name the purine bases.

Adenine and Guanine.

Name the pyrimidine bases.

Cytosine, Thymine, and Uracil.

What sugar is in DNA?

Deoxyribose.

What sugar is in RNA?

Ribose.

What are the base pairs in DNA?

Adenine with Thymine; Cytosine with Guanine.

What are the base pairs in RNA?

Adenine with Uracil; Cytosine with Guanine.

What is a nucleotide composed of?

A phosphate group, a sugar, and a nitrogenous base.

How do nucleotides join to form nucleic acids?

Through phosphodiester bonds to form a long polymer.

What are the two main types of nucleic acids?

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

Which nucleic acid typically forms a double helix with two strands?

DNA.

Which nucleic acid is usually single-stranded and ribose-based?

RNA.

What does ATP stand for and what is its role?

Adenosine Triphosphate; energy transport (energy currency of the cell).

What are the four levels of protein structure?

Primary, Secondary, Tertiary, and Quaternary.

What is primary protein structure?

The unique sequence of amino acids in a polypeptide chain.

What is secondary protein structure?

Folding patterns like alpha-helix and beta-pleated sheet held by hydrogen bonds.

What is tertiary protein structure?

The folded three-dimensional shape of the entire chain due to side-chain interactions.

What is quaternary protein structure?

When several protein chains come together to form a functional protein.

What are common functions of proteins?

Enzymes, structural roles, transport, communication (receptors), defense, and gene regulation.

Approximately what percentage of body mass do proteins constitute?

About 15%.

What is a dipeptide?

Two amino acids linked by a peptide bond with the release of water.

What is a monosaccharide?

A simple sugar (the basic unit of carbohydrates).

Which carbohydrate is known for providing structural support in plants?

Cellulose.

What is the difference between saturated and unsaturated fatty acids?

Saturated fats have no double bonds between carbon atoms; unsaturated fats have one or more double bonds.

What is a triglyceride?

A lipid composed of glycerol bound to three fatty acids.

What is a phospholipid?

A lipid with two fatty acids and a phosphate-containing hydrophilic head; forms a bilayer in water.

What is the difference between the polar head and non-polar tails in phospholipids?

Polar head is hydrophilic; non-polar tails are hydrophobic.

What role does cellulose play in plants?

Structural fibers that provide strength and rigidity.

What is the sugar in DNA and RNA respectively?

DNA uses deoxyribose; RNA uses ribose.

What are the major and minor grooves used for in nucleic acids?

Sites where proteins interact with DNA; important for binding and recognition.

What are the nucleotides joined by to form a polymer in nucleic acids?

Phosphodiester bonds.

What is the difference between DNA and RNA in terms of bases?

DNA: A, T, C, G; RNA: A, U, C, G.

What is the general function of nucleic acids besides storage of information?

Information storage and transfer (and energy transport is a separate role of ATP, not nucleic acids).