Biol 1414 Final

Active Transport

The movement of materials across the cell membrane that requires energy.

Entropy

The measure of disorder or randomness in a chemical reaction; often associated with energy lost as heat.

Tonicity

A measurement of how an extracellular solution can alter a cell's internal volume.

Chemiosmosis

The process where H+ions move against the electrochemical gradient and pass through ATP synthase to create ATP.

Facilitated Diffusion

A type of transport across the cell membrane that uses channel proteins and carrier proteins.

Glycoproteins and Glycolipids

Two types of carbohydrates embedded in the cell membrane that aid in cell-to-cell recognition.

Metabolism

The sum of all the chemical reactions that occur within an organism.

Photoact

The process where chlorophyll A in the reaction center gives up an electron as it becomes excited by capturing sunlight energy.

Electrochemical Gradient

The main mechanism powering passive transport; it is created by both a concentration of a solute and a difference in charge.

Catabolic

A metabolic pathway that releases energy.

Substrate

The molecules an enzyme binds to and acts upon.

Carotenoids

A class of pigments responsible for capturing and dissipating excess energy the plant is exposed to during long summer days.

Potential Energy

Energy stored in the chemical bonds between atoms in molecules such as ATP or Glucose.

Stomata

The structure in plant leaves that allows for gas exchange, specifically taking CO2 in and releasing O2 out.

C3 Plants

Plants that work best in cool, moist climates.

Aerobic respiration

The type of respiration that is more efficient at producing ATP per glucose molecule than anaerobic respiration.

Activation Energy

The energy needed to begin or initiate a chemical reaction.

O2

The final electron acceptor of the electron transport chain in aerobic respiration.

Kinetic Energy

Energy that is associated with motion.

Exergonic Reactions

Reactions that release energy.

Endergonic Reactions

Reactions that require energy.

Hypotonic

An extracellular fluid that has a lower concentration of solute than the cell, causing a net movement of water into the cell.

1st Law of Thermodynamics

States that energy is neither created nor destroyed.

2nd Law of Thermodynamics

States that in all chemical reactions some energy is lost as heat.

Autotrophs

Organisms capable of producing their own food.

Photoautotrophs

Organisms that use light energy from the sun to produce their own food.

Thylakoid

The disk-like structure contained inside the chloroplast where the light-dependent reaction occurs.

NADPH and ATP

Products generated in the thylakoid during the light-dependent reaction that are used in the light-independent reaction.

Chloroplast

The organelle responsible for photosynthesis.

Photosynthetically Active Radiation (PAR)

The wavelengths of light (400-700nm) that our eyes can see and plants use for photosynthesis.

Nonpolar

The type of charge found on the tails of phospholipids in the plasma membrane.

Electromagnetic Spectrum

The entire range of all possible frequencies of light sent to Earth by the sun.

Oxidative Phosphorylation

One of the major steps of cellular respiration which produces a net gain of 32-34 ATP.

Acidic

A solution with a pH less than 7.

Neutral

A solution with a pH = 7.

Basic (Alkaline)

A solution with a pH greater than 7.

Hydrogen Bond

Attraction between slightly positive and slightly negative molecules; responsible for many of water's properties.

Covalent Bond

A chemical bond where atoms share electrons.

Ionic Bond

A bond formed when atoms gain or lose electrons, forming ions.

Ion

An atom or molecule with a positive or negative charge because it gained or lost electrons.

Hydrolysis

A process that breaks polymers into monomers by adding water.

Dehydration synthesis

A process that removes water to build polymers.

Polarity (Water)

Water molecules have distinct positive and negative ends, allowing hydrogen bonds to form.

High specific heat

A property of water that describes its resistance to temperature change.

Carbohydrates

Macromolecules made of monosaccharides that provide quick energy.

Lipids

Macromolecules made of glycerol and fatty acids used for long-term energy storage and membranes.

Proteins

Macromolecules made of amino acids responsible for enzymes, structure, and transport.

Nucleic Acids

Macromolecules made of nucleotides that store genetic information.

Primary Structure

The specific amino acid sequence of a protein.

Secondary Structure

Protein folding consisting of alpha helices and beta pleated sheets.

Tertiary Structure

The overall 3D folding of a protein.

Quaternary Structure

Multiple protein chains working together.

Denaturation

When a protein changes shape and loses function due to heat, pH changes, or chemicals.

Enzymes

Biological catalysts that are proteins and speed up reactions.

Uracil (U)

The nitrogenous base used in RNA instead of Thymine (T).

Complementary Base Pairing

The DNA pairing rule where A pairs with T and C pairs with G.

Nucleotide

The monomer of DNA and RNA.

Transcription

The process where DNA is used to make mRNA; occurs in the nucleus.

Translation

The process where mRNA is used to make protein; occurs on ribosomes with rRNA and tRNA.

Prokaryotes

Small cells with a single circular chromosome, ribosomes, and no membrane-bound organelles.

Nucleus

The organelle that stores DNA.

Rough ER

The organelle that makes and modifies proteins.

Smooth ER

The organelle that makes lipids and carbohydrates.

Golgi Apparatus

The organelle responsible for packaging proteins.

Lysosomes

Organelles that digest waste; mostly found in animal cells.

Cytoskeleton

Structure that gives the cell shape, helps movement, and holds organelles in place.

Mitochondria

The powerhouse of the cell that produces ATP.

Chloroplast

The organelle responsible for photosynthesis in plants.

Central Vacuole

A plant-only organelle that stores water.

Hypothesis

A testable and falsifiable statement in the scientific method.

Scientific Theory

A concept that has extensive evidence and has been repeatedly tested.

Peer Review

The evaluation of scientific papers by experts before publication to ensure trustworthiness.

Qualitative Data

Descriptive data, such as bird color.

Quantitative Data

Numerical data, such as height, mass, or temperature.

Independent Variable

The variable in an experiment that the scientist changes.

Dependent Variable

The variable in an experiment that is measured.

Control Variable

The variable in an experiment that stays the same.

Cell Theory

The theory stating all organisms are made of cells, cells are the basic unit of life, and cells come from pre-existing cells.

Total Magnification

Calculated as Ocular x Objective (e.g., 10x × 10x = 100x)

Chromatin

The substance that makes up chromosomes.

ATP

The primary energy molecule of the cell.

Asexual reproduction

A form of reproduction where organisms produce genetically identical clones of themselves.

Sexual reproduction

A process where parents produce gametes (1n) that fuse to form a genetically unique zygote (2n).

Gametes

Specialized sex cells containing one set of chromosomes (1n) produced by meiosis.

Zygote

A fertilized egg formed when two gametes unite, containing two sets of chromosomes (2n).

Haploid

Cells containing one set of chromosomes, designated as 1n.

Diploid

Cells containing two sets of chromosomes, designated as 2n.

Somatic cells

All cells of a multicellular organism except the gametes.

Homologous chromosomes

Paired chromosomes of a diploid individual containing the same genes in the same location.

Meiosis

A type of nuclear division that forms 1n cells from 2n cells, involving one round of chromosome replication and two rounds of nuclear division.

Synaptonemal complex

A lattice of proteins that connects homologous chromosomes during prophase I.

Synapsis

The tight pairing of homologous chromosomes where genes are aligned perfectly with each other.

Crossing over

The exchange of chromosomal segments between non-sister chromatids, serving as the first source of genetic variation in meiosis.

Recombination nodules

Large protein assemblages that aid the crossing over process by allowing DNA to be cut and reattached.

Tetrad

Pairs of attached homologous chromosomes where all four sister chromatids are visible.

Independent assortment

A second source of genetic diversity occurs during Metaphase I, where homologous chromosomes align randomly and independently, resulting in 2^n possible combinations.

Interkinesis

A short interphase between meiosis I and meiosis II that lacks an S phase, meaning DNA is not duplicated.

Red Queen Hypothesis

An evolutionary theory proposed by Leigh Van Valen stating that species must constantly evolve and adapt to maintain fitness because they coevolve with competing organisms.

Germ cells

Specialized diploid cells produced in the gonads (testes and ovaries) that are capable of both mitosis and meiosis.

Gametophyte

A haploid multicellular plant stage that produces gametes from special cells through mitosis.