General Biology and Biochemistry Lecture Notes

Comprehensive vocabulary flashcards covering general biology topics including early life, scientific methodology, fundamental chemistry, macromolecules, metabolism, cell biology, genetics, biotechnology, and evolutionary principles.

Biology

The study of life.

Hadean

The eon $4.6$ billion years ago when the Earth was formed in a molten state.

Archean

The eon spanning $3.8$ to $2.5$ billion years ago.

Proterozoic

The eon spanning $2.5$ billion to $500$ million years ago, characterized by the emergence of eukaryotes and multicellular animals.

Phanerozoic

The current eon, beginning approximately $500$ million years ago, characterized by fish and amphibians.

Metabolism

The ability of living things to convert molecules into new molecules and into energy.

Entropy

A measure of disorder or the spread of energy; living things must counteract its effects to survive.

Biomes

Broad geographic areas with distinguishing physical features.

Science

The systematic organization of knowledge in a way that can be rationally explained and reliably applied.

Anchoring

A cognitive bias where there is a propensity to rely on the first piece of information or give more weight to the first experiment.

Apophenia

A cognitive bias involving seeing patterns that are not actually there.

Positive Control

An experimental group expected to have a positive result to show the setup is capable of producing results.

Negative Control

An experimental group where conditions produce a negative outcome to identify outside influences.

Inductive Reasoning

A logical process that starts with observations and proposes a hypothesis to explain them.

Deductive Reasoning

A logical process that starts with a hypothesis and predicts the facts that must be observed for the hypothesis to be true.

Hasty Generalization

A logical fallacy where a conclusion is based on insufficient or biased evidence.

Ad Hominem

A logical fallacy that involves attacking the person rather than the argument.

Independent Variable

The parameter that is manipulated by the researcher ($x$), also known as the explanatory variable.

Dependent Variable

The parameter that is measured by the researcher ($y$) in response to changes, also known as the response variable.

Null Hypothesis

The possibility that there is no relationship between variables $X$ and $Y$, indicated as $p \text{-value} > 0.05$.

p-value

The probability that the null hypothesis is correct; typically a value $\text{p} \times 0.05$ means the null hypothesis is rejected.

Big Bang

The start of the universe approximately $13.8$ billion years ago.

Nuclear Fusion

The process in which the nuclei of atoms combine, which occurs in the intense heat and pressure of stars.

Trace Elements

Minerals present in living things in small amounts (< 0.01\text{%}), such as $Fe$, $I$, and $F$.

Dalton (Da)

The unit of mass for protons and neutrons, which have nearly identical mass equal to $1\text{ Dalton}$.

Isotopes

Variants of a chemical element with the same number of protons but a different number of neutrons.

Cation

A positively charged ion.

Anion

A negatively charged ion.

Hydrophilic

A substance that is "water loving" and can dissolve in water, usually ionic or polar compounds.

Hydrophobic

A substance that is "water fearing" and cannot dissolve in water, usually non-polar molecules.

pH

A logarithmic scale representing the concentration of $H^+$ ions, calculated as $\text{pH} = -\text{log}_{10}([H^+])$; lower than $7$ is acidic and higher than $7$ is basic.

Buffers

Weak acids or bases that keep pH from changing significantly by accepting or releasing $H^+$ ions.

Isomers

Compounds with the same molecular formula but different structures and properties.

Monomer

An individual subunit that serves as the building block of a polymer.

Dehydration Reaction

A chemical reaction that connects monomers by a covalent bond while removing one molecule of $H_2O$.

Hydrolysis

A chemical reaction that separates monomers by breaking covalent bonds through the addition of one molecule of $H_2O$.

Glycosidic Linkage

The covalent bond joining two monosaccharides to form a disaccharide.

Saturated Fat

A lipid with no double bonds in the carbon chain, typically solid at room temperature.

Unsaturated Fat

A lipid with one or more double bonds in the carbon chain, typically liquid at room temperature.

Peptide Bond

The covalent bond that joins amino acids together to form a protein.

Denaturation

The process by which a protein's structure is disrupted, causing it to lose its biological function due to heat or pH changes.

Phosphodiester Linkage

The bond that connects nucleotides in a nucleic acid chain.

Catabolic Reaction

A metabolic reaction that releases energy by breaking down complex molecules.

Anabolic Reaction

A metabolic reaction that uses energy to form covalent bonds and build larger molecules.

Energy Coupling

The use of an exergonic process to drive an endergonic one, such as coupling catabolic and anabolic reactions.

Gibbs Free Energy

The portion of a system's energy that can perform work, calculated as $\triangle G = \triangle H - T\triangle S$.

Exergonic Reaction

A spontaneous chemical reaction where $\triangle G < 0$ and energy is released.

Endergonic Reaction

A non-spontaneous chemical reaction where $\triangle G > 0$ and energy must be absorbed.

Active Site

The specific pocket or groove on an enzyme where the substrate enters and the reaction occurs.

Michaelis-Menton Constant (Km)

The substrate concentration at which the reaction velocity is half of its maximum ($\frac{1}{2} V_{max}$).

Competitive Inhibitor

A substance that reduces the activity of an enzyme by mimicking the substrate and binding to the active site.

Non-competitive Inhibitor

A substance that binds to an allosteric site on an enzyme, changing its shape so the active site no longer functions.

Redox Reactions

Chemical reactions involving the transfer of electrons, consisting of oxidation (loss of electrons) and reduction (gain of electrons).

Glycolysis

The first step of cellular respiration occurring in the cytoplasm, which splits glucose into two pyruvate molecules.

Chemiosmosis

The movement of ions, specifically $H^+$, down their concentration gradient through ATP synthase to produce ATP.

Autotroph

An organism that acts as a "self-feeder," producing its own food from sunlight or inorganic substances.

Standard Deviation

A statistical measure describing the variation or spread of data in a sample around the mean.

Standard Error of the Mean (SEM)

A value representing the probability that the sample mean is correct; it decreases as sample size increases.

C3 Plants

Plants that produce a $3\text{-carbon}$ compound ($3\text{-phosphoglycerate}$) as the first organic product of carbon fixation.

Photorespiration

A process where Rubisco adds $O_2$ to the Calvin Cycle instead of $CO_2$, producing no sugar and consuming ATP.

Plasmodesmata

Channels between plant cells that allow for the exchange of small molecules.

Nucleoid

The region in a prokaryotic cell where the circular DNA is located.

Endomembrane System

The group of organelles, including the ER and Golgi apparatus, that works together to modify, package, and transport lipids and proteins.

Tonicity

The ability of a surrounding solution to cause a cell to gain or lose water, categorized as hypertonic, hypotonic, or isotonic.

Ligand

A chemical messenger molecule that binds specifically to a receptor.

Apoptosis

Programmed cell death used to remove unneeded, old, or damaged cells.

Oncogene

A mutated version of a proto-oncogene that has the potential to cause cancer.

Karyotype

An ordered display of an individual's chromosomes.

Haploid (1N)

A cell containing only one set of chromosomes; in humans, this number is $23$.

Diploid (2N)

A cell containing two sets of chromosomes; in humans, this number is $46$.

Synapsis

The pairing of homologous chromosomes during Prophase I of meiosis.

Phenotype

The observable physical traits of an organism.

Genotype

The genetic makeup or potential of an organism.

Epistasis

A genetic phenomenon where the expression of one gene locus influences the phenotype of another gene locus.

Aneuploidy

A condition in which a cell has an incorrect number of chromosomes.

Okazaki Fragments

Short segments of DNA synthesized on the lagging strand during DNA replication.

Introns

Non-coding intervening sequences in periodic mRNA that are cut out during RNA splicing.

Exons

Coding sequences in mRNA that are expressed and joined together during RNA splicing.

Operon

A regulated cluster of genes with related functions in prokaryotes, consisting of a promoter, operator, and genes.

Recombinant DNA

DNA molecules formed by segments from two different sources.

Polymerase Chain Reaction (PCR)

A technique used to amplify short segments of DNA to a high copy number in a test tube.

Morphogen

A transcription factor that diffuses as a concentration gradient within an embryo to determine morphology.

Hox Genes

A family of transcription factors that act as safe-controls to coordinate and synchronize the effects of morphogens during development.

Hardy-Weinberg Equilibrium

The principle that allele frequencies in a population will remain constant unless evolutionary forces act upon them, represented by $p^2 + 2pq + q^2 = 1$.

Genetic Drift

A process in which chance events cause unpredictable fluctuations in allele frequencies from one generation to the next, especially in small populations.

Bottleneck Effect

A sudden reduction in population size due to a catastrophic event, leading to a change in the gene pool.

Phylogenetic Tree

A branching diagram showing the evolutionary history and relationships of a group of organisms.