Molecular Genetics and Inheritance Practice Flashcards

Comprehensive vocabulary flashcards covering biological macromolecules, genetic molecule structures, and the central dogma of molecular biology.

Organic molecule

A molecule that contains carbon (almost always bonded to hydrogen), including all four macromolecule classes.

Monomer

A single small unit that can bond with identical or similar units to form a longer chain.

Polymer

A long chain formed by linking many monomers together.

Dehydration synthesis

A reaction that joins two monomers into a larger molecule by removing a water molecule ($H_2O$); also known as a condensation reaction.

Hydrolysis

A reaction that breaks a bond between monomers by adding a water molecule; it is the reverse of dehydration synthesis.

Carbohydrates

Macromolecules composed of carbon, hydrogen, and oxygen, generally in a ratio of $1$ carbon : $2$ hydrogen : $1$ oxygen.

Monosaccharide

The single-unit monomer of carbohydrates, such as glucose, fructose, and galactose.

Disaccharide

Two monosaccharides joined by a dehydration reaction, such as sucrose, lactose, and maltose.

Polysaccharide

A long polymer of hundreds to thousands of monosaccharides used for energy storage or structural support.

Starch

The energy storage form of glucose found in plants.

Glycogen

The energy storage form of glucose found in the liver and muscles of animals and humans.

Cellulose

A polysaccharide found in plant cell walls that provides structural support and serves as dietary fiber.

Chitin

A polysaccharide used for structural support in insect and crustacean exoskeletons and fungal cell walls.

Lipids

A chemically diverse group of organic compounds unified by being hydrophobic (water-fearing) and insoluble in water.

Triglycerides

Lipids consisting of $1$ glycerol and $3$ fatty acid chains; they provide long-term energy storage, insulation, and organ cushioning.

Phospholipids

Lipids composed of glycerol, $2$ fatty acids, and a phosphate group; they form the structural foundation of cell membranes.

Steroids

Lipids characterized by four fused carbon rings; examples include cholesterol and hormones like testosterone and estrogen.

Waxes

Long-chain hydrocarbon compounds that provide waterproof, protective coatings for plant leaves, bird feathers, and the human ear canal.

Proteins

Macromolecules built from chains of amino acids that carry out cellular work like catalyzing reactions, transport, and defense.

Amino acid

The monomer of proteins, consisting of an amino group ($-NH_2$), a carboxyl group ($-COOH$), a hydrogen atom, and a variable R-group.

R-group

The variable side chain of an amino acid that gives each of the $20$ amino acids its unique chemical personality.

Peptide bond

The covalent bond that links amino acids together to form polypeptide chains.

Primary structure

The linear sequence of amino acids in a protein chain.

Secondary structure

Local, repeating folding patterns in a protein, specifically the $\alpha$-helix (coiled spiral) or $\beta$-pleated sheet (zig-zag), stabilized by hydrogen bonds.

Tertiary structure

The overall $3$-D shape of a single folded polypeptide chain, stabilized by interactions between R-groups.

Quaternary structure

The structure formed when two or more folded polypeptide chains (subunits) join to function as one unit.

Nucleic acids

Macromolecules responsible for storing, transmitting, and expressing genetic information, namely DNA and RNA.

Nucleotide

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

Thymine (T)

A nitrogenous base found only in DNA.

Uracil (U)

A nitrogenous base found only in RNA, where it replaces thymine.

Metabolism

The sum of all chemical reactions occurring in an organism, categorized into catabolism and anabolism.

Catabolism

The metabolic process where complex macromolecules are broken down into monomers via hydrolysis, releasing energy.

Anabolism

The metabolic process where small monomers are linked to build larger macromolecules via dehydration synthesis, consuming energy.

Mitochondrial DNA (mtDNA)

A small amount of DNA located inside the mitochondria that converts food energy into a usable cellular form.

Double helix

The spiral shape of DNA's two long strands, where the sugar-phosphate backbone forms the rails and base pairs form the rungs.

Base pairing rule

The rule that DNA bases pair fixedly: adenine (A) with thymine (T), and cytosine (C) with guanine (G).

Replication

The process where DNA makes an exact copy of itself using each strand as a template.

Messenger RNA (mRNA)

The type of RNA that copies genetic instructions from DNA in the nucleus and carries them to the ribosomes.

Transfer RNA (tRNA)

The type of RNA that brings the correct amino acids to the ribosome to build proteins.

Ribosomal RNA (rRNA)

The type of RNA that forms the core structural and functional part of the ribosome.

Central Dogma

The principle that genetic information flows in one direction: DNA $\rightarrow$ RNA $\rightarrow$ Protein.

Transcription

The process of copying DNA's genetic code into a portable messenger molecule (mRNA) within the nucleus.

Translation

The process occurring at the ribosome where the mRNA message is read and converted into a chain of amino acids.