BIOL 1140 Exam 1 Study Guide

A comprehensive set of vocabulary flashcards covering the core concepts of BIOL 1140 Exam 1, including the scientific method, chemistry of life, macromolecules, and cell organelles.

Hypothesis

A testable and falsifiable explanation for a set of observations.

Theory

A widely accepted explanatory idea that is broader in scope than a hypothesis and is supported by a large body of evidence.

Null hypothesis

A hypothesis that proposes there is no significant difference between specified populations, often used in statistical testing.

Observational research

A research method that involves observing and recording behavior or phenomena without manipulating variables.

Manipulative research

Research where the investigator actively manipulates one or more variables to determine their effect on a system.

Control group

The group in an experiment that serves as a standard for comparison and is not exposed to the experimental treatment.

Variables

Factors or conditions in an experiment that can be changed, controlled, or measured.

Controlled variables

The factors in an experiment that must be kept constant to ensure the results are due to the manipulation of the independent variable.

Protons

Subatomic particles with a single positive electrical charge ($+$) found in the nucleus of an atom.

Neutrons

Subatomic particles with no electrical charge (neutral) found in the nucleus of an atom.

Electrons

Subatomic particles with a single negative electrical charge ($-$) that move around the nucleus in energy levels or shells.

Isotope

One of several atomic forms of an element, each with the same number of protons but a different number of neutrons.

Covalent bond

A type of strong chemical bond in which two atoms share one or more pairs of valence electrons; examples include hydrogen gas ($H_2$).

Polar covalent bond

A covalent bond between atoms that differ in electronegativity, where electrons are shared unequally, creating partial charges.

Non-polar covalent bond

A covalent bond in which electrons are shared equally between two atoms of similar electronegativity.

Electronegativity

The measure of an atom's attraction for the shared electrons in a bond.

Ionic bond

A chemical bond resulting from the attraction between oppositely charged ions, formed via electron transfer; an example is sodium chloride ($NaCl$).

Hydrogen bond

A type of weak chemical bond formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule.

Ion

An atom or molecule with a net electric charge due to the loss or gain of one or more electrons.

Solute

A substance that is dissolved in a solution.

Solvent

The dissolving agent of a solution; water is the most common biological solvent.

Acid

A substance that increases the hydrogen ion ($H^+$) concentration in a solution.

Base

A substance that decreases the hydrogen ion ($H^+$) concentration in a solution.

Buffer

A chemical substance that minimizes changes in $pH$ by accepting $H^+$ from or donating $H^+$ to solutions.

Monomers

The subunit that serves as the building block of a polymer.

Polymers

A large molecule consisting of many identical or similar monomers linked together by covalent bonds.

Dehydration synthesis

A chemical reaction in which two molecules become covalently bonded to each other with the removal of a water molecule ($H_2O$).

Hydrolysis

A chemical reaction that breaks bonds between two molecules by the addition of water; the process used to break down polymers into monomers.

Polysaccharide

A carbohydrate polymer of many monosaccharides (sugars) linked by dehydration reactions.

Monosaccharide

The simplest carbohydrate; a simple sugar that serves as a monomer for disaccharides and polysaccharides.

Disaccharides

A sugar molecule consisting of two monosaccharides linked by a dehydration reaction.

Fats (triglycerides)

A lipid composed of three fatty acids linked to one glycerol molecule; used primarily for energy storage.

Phospholipids

A lipid made up of glycerol joined to two fatty acids and a phosphate group; forms bilayers that make up cell membranes.

Steroids

A type of lipid whose carbon skeleton is in the form of four fused rings; examples include cholesterol and certain hormones.

Amino acid

An organic molecule serving as the monomer of proteins, containing a carboxyl group and an amino group.

Polypeptide

A polymer (chain) of amino acids linked by peptide bonds.

Peptide bond

The covalent bond between two amino acid units in a polypeptide, formed by a dehydration reaction.

Organelle

A membrane-enclosed structure with a specialized function within a eukaryotic cell.

Endomembrane system

A network of membranes inside and around a eukaryotic cell, including the nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles, and plasma membrane.

Smooth ER

That portion of the endoplasmic reticulum that lacks ribosomes and is involved in lipid synthesis and detoxification.

Rough ER

That portion of the endoplasmic reticulum with ribosomes attached that make membrane proteins and secretory proteins.

Golgi apparatus

An organelle in eukaryotic cells consisting of stacks of membranous sacs that modify, store, and ship products of the endoplasmic reticulum.

Lysosomes

A digestive organelle in eukaryotic cells; contains hydrolytic enzymes that digest engulfed food or damaged organelles.

Mitochondria

An organelle in eukaryotic cells where cellular respiration occurs and most of the cell's ATP is made.

Chloroplasts

An organelle found in plants and algae that absorbs sunlight and uses it to drive the synthesis of organic compounds (photosynthesis).

Cristae

Infoldings of the inner mitochondrial membrane that increase surface area for chemical reactions.

Extracellular matrix (ECM)

The meshwork surrounding animal cells, consisting of glycoproteins and polysaccharides synthesized and secreted by the cells.