Unit 1 Biochemistry: Macromolecules and Organic Compounds

A comprehensive set of Q&A flashcards covering atoms, bonds, macromolecules, and the four major biomolecule groups (carbohydrates, proteins, lipids, nucleic acids) as presented in the lecture notes.

What is the smallest basic unit of matter?

Atom.

What is an element?

A different kind of atom; each different kind of atom is a different element (e.g., C, H, O, N).

What is a compound?

Two or more elements chemically combined in definite proportions (e.g., CO2, H2O, NaCl, C6H12O6).

Differentiate inorganic and organic compounds.

Inorganic compounds come from nonliving substances; organic compounds come from living substances.

What is a chemical reaction?

A process leading to changes in matter; reactants become products.

What happens to energy in chemical reactions?

Energy changes; breaking bonds requires energy input, and forming new bonds releases energy; the calorie is a unit of energy.

What is the basic building block of life?

Carbon.

Give an example of an organic compound and an exception to carbon-based rules.

Glucose (C6H12O6) is an organic compound; carbon dioxide (CO2) is an exception in some contexts.

What are macromolecules?

Large complex organic compounds; also called polymers or biomolecules.

What is a polymer?

A large compound formed by linking monomers; synonymous with macromolecule.

What is a monomer?

A small building block that can join to form larger compounds (polymers).

What happens in dehydration synthesis?

Monomers join to form polymers with removal of water (De = removal, hydr = water, syn = together).

What happens in hydrolysis?

Polymers are broken into monomers by adding water; water is a reactant.

Name the four major groups of organic compounds.

Carbohydrates, proteins, lipids, nucleic acids.

What are macromolecules also called?

Polymers or biomolecules; large carbon-based molecules.

Explain the relationship among macromolecules, polymers, and biomolecules.

Macromolecules = polymers = biomolecules; all are carbon-based.

What are the primary functions of carbohydrates?

Provide energy; maintain structure; some roles in cell-to-cell communication.

What is the general formula ratio for carbohydrates?

C:H:O = 1:2:1.

What is the most common carbohydrate in cells?

Glucose (C6H12O6).

What are the three groups of carbohydrates?

Monosaccharides, disaccharides, polysaccharides.

Name three common monosaccharides.

Glucose, fructose, galactose (isomers have the same formula but different structures).

What is a disaccharide?

A double sugar formed by joining two monosaccharides; examples include sucrose, maltose, lactose.

What are polysaccharides and examples?

Many sugars; starch (plants), glycogen (animals), cellulose (plants).

What are the roles of starch, glycogen, and cellulose?

Starch stores energy in plants; glycogen stores energy in animals; cellulose provides structure in plants (dietary fiber).

What are proteins?

Functional polypeptides; polymers of amino acids; include enzymes, antibodies, transport proteins.

What is the monomer of proteins?

Amino acids (20 different amino acids).

What elements do proteins contain?

Carbon, hydrogen, oxygen, and nitrogen (C, H, O, N).

What determines protein function?

The sequence of amino acids and the 3D folding of the protein (structure determines function).

What is denaturation?

A change in shape that results in loss of function; caused by temperature, pH changes, or inhibitors.

What are enzymes?

Biological catalysts that speed up chemical reactions; most are proteins; not consumed in reactions; highly specific to substrates.

What is the active site?

The region of the enzyme where the substrate binds; determines specificity (Lock and Key model).

What is a substrate?

The substance upon which an enzyme acts.

How are enzymes named?

Add -ase to the substrate (e.g., maltose → maltase; protein → protease).

What effect do enzymes have on activation energy?

They lower activation energy, speeding up the reaction.

What are lipids?

Biomolecules for energy storage, hormones, and membranes; include fats, oils, phospholipids, cholesterol, steroids, and waxes.

What are the monomer and polymer of lipids?

Monomer: glycerol and fatty acids; polymer: triglyceride.

How do saturated and unsaturated fatty acids differ?

Saturated: no double bonds; typically from animal fats; associated with higher LDL cholesterol. Unsaturated: one or more double bonds; from plant oils; healthier; raise HDL and lower LDL.

What is cholesterol?

A lipid in cell membranes; forms LDL (bad) and HDL (good) cholesterol; excess LDL can deposit in arteries.

What are the two main types of cholesterol and their roles?

LDL (bad) delivers cholesterol to cells; HDL (good) helps remove excess cholesterol from arteries.

What are phospholipids and their role in membranes?

Phospholipids have hydrophilic heads and hydrophobic tails; they form the phospholipid bilayer of cell membranes.

What are steroids in lipids?

A type of lipid hormone that can cross cell membranes to affect cells.

What are waxes used for in plants?

Waxes help make plant leaves waterproof.

What are nucleic acids?

Store and transmit genetic information; include DNA and RNA; monomer is nucleotide.

What elements do nucleotides contain?

Carbon, hydrogen, oxygen, nitrogen, and phosphorus (C, H, O, N, P).

What are DNA and RNA bases?

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

What is ATP and its role?

Adenosine triphosphate; stores energy from food and releases it to fuel cellular processes; contains three phosphate groups.

What are the three parts of a nucleotide?

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

Which organelle is associated with carbohydrate metabolism and glucose breakdown?

Mitochondria.

Which organelle makes glucose in plants?

Chloroplast (sites of photosynthesis).

What is the basic structure of the cell membrane?

Phospholipid bilayer with hydrophilic heads and hydrophobic tails; contains cholesterol and proteins.