Bio exam 2

Monomer

The basic unit that serves as the building block of a polymer, such as monosaccharides for carbohydrates.

Glycosidic linkage

The bond formed between two monosaccharides in a disaccharide.

Hemiacetal linkage

The type of bond formed between an aldehyde and a hydroxyl group when glucose is in aqueous solution.

Polysaccharide

A carbohydrate that consists of multiple monosaccharide units linked together, such as starch and glycogen.

Cellulose

A major component of plant cell walls, known for its rigidity and resistance to digestion by most animals.

Nucleotide

The building block of nucleic acids, composed of a nitrogenous base, a five-carbon sugar, and a phosphate group.

Phosphodiester linkage

The bond that links nucleotides together in a nucleic acid strand.

Purines

A type of nitrogenous base in nucleic acids that includes adenine and guanine.

Pyrimidines

A type of nitrogenous base in nucleic acids that includes cytosine, thymine, and uracil.

Osmosis

The movement of water across a semipermeable membrane from a region of lower solute concentration to higher solute concentration.

Isotonic solution

A solution with the same solute concentration as that inside a cell, resulting in no net water movement.

Hypertonic solution

A solution with a higher solute concentration than that inside a cell, causing the cell to lose water.

Hypotonic solution

A solution with a lower solute concentration than that inside a cell, causing the cell to gain water.

Exocytosis

The process by which cells secrete or expel molecules to the outside.

Endocytosis

The process by which cells take in macromolecules from the outside.

Phagocytosis

A type of endocytosis known as 'cellular eating' where a cell engulfs large particles or cells.

Pinocytosis

A type of endocytosis known as 'cellular drinking' where a cell takes in liquid from the surrounding environment.

Enzyme

A biological catalyst that speeds up chemical reactions by lowering the activation energy.

Catabolism

Metabolic pathways that break down molecules, resulting in the release of energy.

Anabolism

Metabolic pathways that build molecules, requiring an input of energy.

Activation energy (EA)

The minimum amount of energy needed to initiate a chemical reaction.

Exergonic reaction

A reaction that releases free energy; ΔG is negative.

Endergonic reaction

A reaction that absorbs free energy; ΔG is positive.

First Law of Thermodynamics

Energy cannot be created or destroyed, only transformed.

Second Law of Thermodynamics

Every energy transfer increases the entropy (disorder) of the universe.

Entropy

A measure of disorder or randomness in a system.

Macromolecule

A large molecule, typically formed from smaller units (monomers), essential for life, such as carbohydrates, proteins, lipids, and nucleic acids.

Protein

A macromolecule made of amino acids that plays critical roles in the body, including catalyzing biochemical reactions and providing structure.

Amino Acid

The building block of proteins, consisting of an amine group, a carboxylic acid group, and a side chain that determines its properties.

Lipid

A diverse group of hydrophobic molecules, including fats, oils, and phospholipids, important for energy storage and cell membrane structure.

Nucleic Acid

A macromolecule, such as DNA or RNA, composed of nucleotide monomers that store and transmit genetic information.

Dehydration Synthesis

A chemical reaction that links monomers together by removing water, forming polymers.

Hydrolysis

A reaction that breaks down polymers into monomers by adding water.

Enzyme-substrate complex

The temporary complex formed when an enzyme binds to its substrate, facilitating a biochemical reaction.

Denaturation

The process in which a protein loses its native structure, often due to temperature or pH changes, resulting in loss of function.

Coenzyme

A non-protein organic molecule that assists enzymes in catalyzing reactions, often derived from vitamins.

Hydrophilic

A property of molecules that are attracted to water and can dissolve in it.

Hydrophobic

A property of molecules that repel water and do not dissolve in it.

Phospholipid

A type of lipid molecule that forms the bilayer of cell membranes, consisting of hydrophilic heads and hydrophobic tails.

Cell Membrane

A biological membrane that separates and protects the interior of a cell from the external environment.

Genome

The complete set of genes or genetic material present in a cell or organism.

Chromosome

A structure made of DNA and proteins that contains genetic information.

Transcription

The process by which the genetic information in DNA is copied to mRNA.

Translation

The process by which mRNA is decoded by a ribosome to produce a polypeptide or protein.

Ribosome

A cellular structure that synthesizes proteins by linking amino acids together in the order specified by mRNA.

Antibody

A protein produced by the immune system that recognizes and neutralizes foreign substances, such as pathogens.