BIO 111 FINAL EXAM REVIEW

Atom

Smallest unit of matter retaining element properties; made of protons, neutrons, electrons.

Element

Pure substance of one atom type; cannot be chemically simplified.

Essential Elements

Elements needed in large amounts for survival, growth, reproduction (e.g., C, H, O, N, P, S, Ca, K, Na, Cl, Mg, Fe).

Atomic Number (Z)

Number of protons in an atom; defines the element.

Mass Number (A)

Total number of protons and neutrons in an atom.

Isotopes

Atoms of the same element with different numbers of neutrons; neutral charge and altered mass.

Ions

Atoms or molecules with net charge due to loss or gain of electrons.

Electron Shell

Region around the nucleus where electrons are likely to be found.

Valence Electrons

Electrons in the outermost shell that determine an atom's reactivity.

Electronegativity (EN)

The tendency of an atom to attract shared electrons in a covalent bond.

Ionic Bonds

Bonds formed by the complete transfer of electrons from one atom to another.

Covalent Bonds

Bonds formed by the sharing of electron pairs between atoms.

Hydrogen Bonds (H-bonds)

Weak attractions between a hydrogen atom bonded to an electronegative atom and another electronegative atom.

Hydrophilic

Substances that are polar or charged and can interact with water.

Hydrophobic

Substances that lack polarity and cannot interact with water.

pH

A measure of the hydrogen ion concentration in a solution; indicates acidity or alkalinity.

Buffers

Substances that stabilize pH by absorbing or releasing hydrogen ions.

Dehydration Synthesis

Process of forming covalent bonds by removing water molecules between monomers.

Macromolecules

Large complex molecules including carbohydrates, proteins, lipids, and nucleic acids.

Cell Theory

The theory that states all living things are composed of cells, and all cells arise from pre-existing cells.

Prokaryotic Cells

Cells without a nucleus or other membrane-bound organelles.

Eukaryotic Cells

Cells with a nucleus and membrane-bound organelles.

ATP (Adenosine Triphosphate)

Molecule that stores and transfers energy in cells.

Enzymes

Biological catalysts that speed up chemical reactions by lowering activation energy.

Diffusion

The movement of molecules from an area of high concentration to an area of low concentration.

Osmosis

The diffusion of water across a selectively permeable membrane.

Fermentation

Anaerobic process that produces energy by converting sugars to acids, gases, or alcohol.

Photosynthesis

The process by which plants use light energy to produce glucose and oxygen from carbon dioxide and water.

Mitosis

A process of cell division that results in two genetically identical daughter cells.

Meiosis

A specialized form of cell division that reduces chromosome number, producing four genetically diverse haploid gametes.

Genotype

The genetic makeup of an organism; the alleles present.

Phenotype

The observable traits of an organism, influenced by genotype and environment.

Mutation

A change in the DNA sequence that can lead to alterations in gene expression or function.

Natural Selection

The process where organisms better adapted to their environment tend to survive and produce more offspring.

Gene Therapy

A technique that modifies or manipulates the expression of a gene to treat disease.

Recombinant DNA

DNA produced by combining DNA from different sources.

Genome Editing

The process of making changes to the DNA of a cell or organism.

Transgenic Organism

An organism that contains a gene or genes which have been artificially inserted instead of the organism acquiring them through reproduction.

Polymerase Chain Reaction (PCR)

A technique used to amplify a specific DNA segment through repeated cycles.

Gel Electrophoresis

A method for separating DNA fragments based on their size.

Stem Cells

Undifferentiated cells capable of self-renewal and differentiation into specialized cell types.

Hydroxyl

A polar functional group (-OH) that can form hydrogen bonds and increases solubility in water.

Carboxyl

An acidic functional group (-COOH) that acts by donating H+, important in amino acids and fatty acids.

Amino

A basic functional group (-NH2) that can accept H+, forming part of amino acids.

Phosphate

A functional group (-PO4) that contributes to energy transfer in ATP and DNA structure.

Methyl

A nonpolar, hydrophobic functional group (-CH3) that influences the shape and function of organic molecules.

pH of Acids

Acids have a pH less than 7.

Bases

Substances with pH > 7, characterized by low H^+ concentration.

Carbohydrates

Composed of C, H, O; serve as primary energy sources and structural components; built from simple sugars (monosaccharides).

Lipids

Composed predominantly of C and H; essential for energy storage, cell membranes, and hormonal regulation; include fatty acids and cholesterol.

Proteins

Composed of C, H, O, N; crucial for enzymatic activity, cellular structure, and signaling; built from amino acids linked by peptide bonds.

Nucleic Acids

Composed of C, H, O, N, P; vital for storing and transferring genetic information (DNA and RNA); built from nucleotides.

Prokaryotic Cell

Small, ancient cells (0.1-5µm); lack a nucleus and membrane-bound organelles; contain circular DNA (nucleoid), cell wall (peptidoglycan), and ribosomes.

Eukaryotic Cell

Larger, younger cells (10-100µm) with a true nucleus and various membrane-bound organelles like mitochondria, chloroplasts (in plants), Golgi, and ER.

Plasma Membrane

A phospholipid bilayer (Fluid Mosaic Model) that forms the cell boundary, regulating substance passage due to its selective semi-permeability.

Mitochondria

A double-membraned eukaryotic organelle with its own DNA, primarily responsible for generating ATP through cellular respiration.

Chloroplast

A double-membraned organelle found in plant and algal cells that contains chlorophyll and is the site where photosynthesis occurs.

Endosymbiotic Theory

A theory suggesting that mitochondria and chloroplasts originated from free-living bacteria that were engulfed by ancestral host cells, explaining their dual membranes and independent DNA.

Diffusion

Net movement from high to low concentration.

Osmosis

Diffusion of water.

Tonicity

Cell response to solute concentration.

Hypertonic

Cell shrinks (water moves out).

Hypotonic

Cell swells (water moves in).

Isotonic

No net water movement in/out of cell.

Central Vacuole

Maintains turgor pressure in plants.

Pumps

Active transport proteins moving molecules against a concentration gradient.

Bulk Transport

Moving large amounts of substances across the membrane (Endocytosis/Exocytosis).

Endocytosis

Bulk transport of substances into the cell.

Exocytosis

Bulk transport of substances out of the cell.

Chlorophyll a

Primary pigment in leaves that absorbs violet-blue and red light, reflecting green light, which makes leaves appear green.

Chloroplast

The double-membraned organelle in plant cells where photosynthesis occurs, containing thylakoids (stacked into grana) and stroma.

Light Reactions

The first stage of photosynthesis, occurring in the thylakoid membranes, which uses light energy to split H2O (releasing O2), excite electrons, and produce ATP and NADPH.

Carbon Reactions

The second stage of photosynthesis (also known as the Calvin Cycle), occurring in the stroma, which uses ATP and NADPH from the light reactions to convert CO_2 into glucose.

Oxygen Gas

Mainly from the splitting of H_2O during photosynthesis and from oceanic algae.

Gene Expression

Process from DNA to functional product, involving Transcription (DNA to RNA) and Translation (mRNA to Protein).

Mutations

Changes in DNA sequence, including Point Mutations (single nucleotide changes) and Frameshift Mutations (insertions/deletions altering reading frame).

Gene Regulation

Control mechanisms determining when and how genes are expressed, such as Epigenetics and Prokaryotic Operons.

Eukaryotic Cell Cycle & Mitosis

Ordered sequence of phases (G1 $\rightarrow$ S $\rightarrow$ G2 $\rightarrow$ M) where a eukaryotic cell grows, replicates DNA, and divides into two identical daughter cells.

Meiosis

Sexual reproduction process that reduces chromosome number (2n \rightarrow n) and creates genetic diversity, resulting in four unique haploid gametes.

Mendel's Laws (of Segregation & Independent Assortment)

States that allele pairs separate during gamete formation and alleles of different genes assort independently.

Genetic Engineering & Biotechnology

DNA manipulation techniques (e.g., recombinant DNA, gene editing) and related applications, including cloning and gene therapy.