Bio 110 Lecture Flashcards

Vocabulary practice flashcards covering core topics in general biology and biochemistry, including scientific methods, taxonomy, basic chemistry, biological macromolecules, and DNA replication.

Biology

The scientific study of life.

Science

Knowledge covering general truths or laws, particularly those tested via the scientific method.

Natural Sciences

Fields of science related to the physical world, divided into life sciences (studying living things like biology) and physical sciences (studying nonliving matter like chemistry).

Inductive Reasoning

A form of scientific reasoning that moves from specific observations to a general conclusion.

Deductive Reasoning

A form of scientific reasoning that moves from a general principle to predict specific results.

Scientific Method

A systematic process of discovery involving observations, asking questions, forming hypotheses, making predictions, running experiments/conclusions, and developing theories.

Hypothesis

A proposed explanation that answers a question, which can be tested and either supported, rejected, or revised.

Theory

A tested and confirmed explanation for observations or phenomena, developed when a hypothesis is consistently supported over time.

Homeostasis

The ability of an organism to maintain stable internal conditions despite external changes.

Prokaryotes

Single-celled organisms that lack a membrane-bound nucleus and membrane-bound organelles.

Eukaryotes

Organisms composed of cells containing membrane-bound organelles and a membrane-bound nucleus.

Phylogenetic Tree

A diagram showing evolutionary relationships among biological species based on similarities and differences in physical or genetic traits.

Three Domains of Life

The overarching biological classification system proposed by Carl Woese in 1977, dividing life into Bacteria, Archaea, and Eukarya.

Atom

The simplest unit of an element that retains all chemical properties of that element.

Atomic Number

The number of protons in an atom's nucleus, which equals the number of electrons in a neutral atom.

Mass Number

The total number of protons and neutrons in the nucleus of an atom.

Isotopes

Different forms of an element that have the same number of protons but a different number of neutrons.

Radioisotopes

Unstable isotopes that decay at a constant rate over time (e.g. Carbon-14).

Carbon-14

A radioactive isotope of carbon containing 6 protons and 8 neutrons, with a half-life of 5,730 years used for radiocarbon dating of organic remains.

Octet Rule

The principle stating that atoms are most stable when their outermost electron shell contains eight electrons.

Ionic Bonds

Bonds formed when one atom donates or takes electrons from another atom, creating charged ions that attract each other.

Covalent Bonds

Strong chemical bonds formed when two or more atoms share electrons.

Polar Covalent Bonds

Covalent bonds in which electrons are shared unequally due to differing electronegativities, resulting in partial positive and negative charges.

Nonpolar Covalent Bonds

Covalent bonds in which electrons are shared equally between atoms.

Hydrogen Bonds

Weak electrostatic attractions between a partially positive hydrogen atom and a partially negative atom in another molecule.

Hydrophilic

Refers to polar or ionic substances that readily interact with or dissolve in water.

Hydrophobic

Refers to nonpolar substances that do not interact with or dissolve in water (e.g. oil)

Cohesion

The intermolecular attraction between like water molecules, responsible for surface tension.

Adhesion

The attraction between water molecules and other polar surfaces, enabling capillary action.

Buffers

Substances that absorb excess $H^+$ or $OH^-$ ions to maintain a stable pH in biological solutions.

Hydrocarbons

Organic compounds composed exclusively of carbon and hydrogen atoms.

Isomers

Molecules that share the same chemical formula but differ in their structural arrangement or spatial orientation.

Functional Groups

Specific clusters of atoms attached to carbon backbones that confer distinctive chemical properties to organic molecules (hydroxyl, carboxyl, amino, phosphate, and methyl).

Monomers

Small organic subunits that serve as the building blocks for larger biological polymers.

Polymers

Large molecules formed by joining monomers together through covalent bonds.

Dehydration Synthesis

A condensation reaction that joins monomers into polymers by forming covalent bonds and releasing a water molecule ($H_2O$).

Hydrolysis

A chemical process that breaks polymers down into individual monomers by adding a water molecule.

Monosaccharides

Simple sugar monomers containing 3 to 7 carbon atoms with the general formula $(CH_2O)_n$.

Disaccharides

Sugars composed of two monosaccharide units joined by a covalent glycosidic bond through dehydration synthesis.

Starch

A storage polysaccharide in plants composed of unbranched amylose ($\alpha\,1\text{-}4$ bonds) and branched amylopectin ($\alpha\,1\text{-}6$ bonds).

Glycogen

A highly branched energy storage polysaccharide made of glucose monomers in animal liver and muscle cells.

Cellulose

A structural polysaccharide in plant cell walls formed by linear chains of glucose joined by $\beta\,1\text{-}4$ linkages.

Chitin

A nitrogen-containing polysaccharide that structuralizes fungal cell walls and arthropod exoskeletons.

Saturated Fatty Acids

Fatty acids containing only single carbon-carbon bonds, maximizing hydrogen content, and packing tightly as solids at room temperature (e.g. butter).

Unsaturated Fatty Acids

Fatty acids containing one or more double $C=C$ bonds whose cis configurations create kinks preventing tight packing, making them liquid at room temperature (e.g. oil).

Phospholipids

Amphipathic molecules consisting of a glycerol backbone, two fatty acid tails, and a phosphate group, forming the cellular membrane bilayer.

Steroids

Lipids characterized by a core structure of four fused carbon rings, such as cholesterol.

Peptide Bonds

Covalent bonds linking amino acids together via dehydration synthesis to form polypeptide chains.

Denaturation

The loss of a protein's secondary, tertiary, or quaternary structure and function due to environmental stresses like changes in temperature or pH.

Four Levels of Protein Structure

The structural organizational levels of proteins: primary (sequence), secondary ($\alpha$-helices/$\beta$-sheets), tertiary (3D shape), and quaternary (subunit assembly).

Primary Structure

The linear sequence of amino acids in a polypeptide chain joined by covalent peptide bonds.

Secondary Structure

Local folding patterns in a polypeptide chain, such as $\alpha$-helices and $\beta$-pleated sheets, stabilized by hydrogen bonds along the backbone.

Tertiary Structure

The overall three-dimensional shape of a protein created by chemical interactions among variable R groups.

Quaternary Structure

The structural arrangement resulting from the interaction and combination of multiple polypeptide subunits.

Nucleotides

Monomers of nucleic acids composed of a 5-carbon pentose sugar, a phosphate group, and a nitrogenous base.

Purines

Double-ring nitrogenous bases found in DNA and RNA, including Adenine (A) and Guanine (G).

Pyrimidines

Single-ring nitrogenous bases, including Cytosine (C), Thymine (T) in DNA, and Uracil (U) in RNA.

Central Dogma

The biological principle stating that genetic information flows sequentially from DNA to RNA (via transcription) to Protein (via translation).

Transforming Principle

The phenomenon discovered by Frederick Griffith (1928) and proven to be DNA by Avery, MacLeod, and McCarthy (1944) where genetic material is transferred between bacteria.

Helicase

An enzyme that unwinds and separates the double-stranded DNA molecule at the replication origin.

Single-strand Binding Proteins (SSB)

Proteins that bind to separated DNA strands to prevent them from rewinding into a double helix during replication.

Topoisomerase

An enzyme that alleviates supercoiling and over-winding stress ahead of the replication fork.

Primase

An enzyme that synthesizes an RNA primer to provide a free $3'$ -OH group for DNA polymerase to begin synthesis.

DNA Polymerase III

The main prokaryotic enzyme that adds DNA nucleotides in the $5'$ to $3'$ direction during replication.

DNA Polymerase I

An enzyme that removes RNA primers and replaces them with DNA nucleotides during DNA replication.

DNA Ligase

An enzyme that joins Okazaki fragments together by forming phosphodiester bonds on the lagging strand backbone.

DNA Replication Machinery

The complex enzymatic machinery, including helicase, primase, DNA polymerases, and ligase, operating at the replication fork.

Telomeres

Repetitive non-coding DNA sequences located at the ends of linear chromosomes that safeguard genetic code from degradation.

Telomerase

An enzyme active in germ and stem cells that maintains telomere length to prevent chromosomal shortening.

Nucleotide Excision Repair

A DNA repair mechanism that cuts out and replaces damaged bases, such as UV-induced thymine dimers, by cleaving the DNA backbone on both sides of the lesion.

Frameshift Mutations

Mutations caused by the insertion or deletion of nucleotides that shift the genetic reading frame and alter all subsequent amino acids.

mRNA

A molecule that conveys genetic information from DNA to the ribosome, where it is translated into protein.

tRNA

A type of RNA that brings amino acids to the ribosome during protein synthesis, matching the appropriate codon on the mRNA.

rRNA

Combines proteins to form ribosomes. It provides structural support and acts as a catalyst (ribosome) to form peptide bonds between amino acids.