BIO 1203 Lecture Notes Review

Flashcards based on lecture notes to help students review key concepts for their exam.

Define a hypothesis in the context of scientific inquiry.

A suggested explanation that accounts for observations; a proposition that might be true.

What is a scientific theory?

A well-tested, accepted principle or body of knowledge, supported by evidence.

Define evolution.

Genetic change in a population of organisms over successive generations; leads to progressive change from simple to complex.

What is natural selection?

A mechanism for evolution resulting from the differential reproduction of genotypes due to environmental factors.

What are atoms?

The basic building blocks of matter, composed of protons, neutrons, and electrons.

What is a neutron?

A neutrally charged subatomic particle located in the nucleus of an atom, weighing approximately 1 amu.

What is an isotope?

Atoms of the same element that have a different number of neutrons.

What is a proton?

A positively charged subatomic particle located in the nucleus of an atom, weighing approximately 1 amu, and determining the element's identity (atomic number).

What are valence electrons?

Electrons found on the outermost energy shell, participating in the formation of chemical bonds, and greatly impacting stability/reactivity.

What are elements?

Substances that cannot be broken down into simpler substances by normal chemical means (e.g., carbon, oxygen, hydrogen, nitrogen).

What is atomic number?

The number of protons in an atom, determining its elemental identity.

What is atomic mass?

The sum of the protons and neutrons in an atom.

What is half-life?

The time it takes for one-half of the atoms in a sample to decay; radioactive isotopes decay over time.

What is a cation?

A positively charged ion where the number of protons outweighs the number of electrons; typically metals.

What is an anion?

A negatively charged ion where the number of electrons outweighs the number of protons; typically nonmetals.

Define oxidation.

A reaction where a reactant loses electrons.

Define reduction.

A reaction where a reactant gains electrons.

Describe ionic bonds.

Formed by the attraction of oppositely charged ions through the transfer of electrons; typically formed between a metal and a nonmetal.

Describe covalent bonds.

Formed by the sharing of two or more valence electrons by atoms; generally have a net charge of zero.

What is electronegativity?

An atom's affinity for electrons; a measure of an atom's ability to attract shared electrons to itself.

Describe nonpolar covalent bonds.

Equal sharing of electrons.

Describe polar covalent bonds.

Unequal sharing of electrons.

What is a hydrogen bond?

A chemical bond specifically between a hydrogen atom and a highly electronegative atom (Nitrogen, Oxygen, or Fluorine).

What is cohesion in water molecules?

Water molecules' ability to stick together due to the polarity of the molecules and hydrogen bonds.

What is adhesion in water molecules?

Water molecules' ability to stick to other polar molecules.

Define hydrophilic.

Water loving.

Define hydrophobic.

Water fearing.

What elements are primarily found in organic molecules?

Carbon, hydrogen, oxygen, and nitrogen (CHON).

What influences chemical reactions?

Temperature, concentration of reactants and products, and catalysts.

Describe acids.

High concentration of hydrogen ions (when dissociated in water, acids increase the hydrogen ion concentration) with a pH of less than 7.

Describe bases.

High concentration of hydroxide ions (OH-) (when dissociated in water, bases increase the hydroxide ion concentration) with a pH of greater than 7.

What characterizes organic molecules?

A carbon backbone that allows for formations that contribute to structure and function.

What is a hydrocarbon?

A molecule consisting of only carbon and hydrogen (e.g., methane).

Describe lipids.

Macromolecules that are hydrophobic nonpolar molecules that are fat soluble, made up of carbon, oxygen, and hydrogen (e.g., triglycerides, phospholipids, and cholesterol).

Describe carbohydrates.

Macromolecules that are primarily used for energy storage and have an empirical formula of CH2O (sugars, starches, and fiber).

Describe Proteins.

Macromolecules/polymers made up of amino acids linked by peptide bonds to form polypeptides; has four levels of structure: primary, secondary, tertiary, quaternary.

Describe Nucleic acids.

Polymers made up of nucleotide monomers that contain a sugar, phosphate group, and nitrogenous base.

What is hydrolysis?

A process that involves water to break down complex molecules by the formation of a cleavage between covalent bonds of monomers (Polymers → monomers).

What is Dehydration synthesis?

Involves the removal of a water molecule in order to join two monomers, building up macromolecules.

How does surface area affect diffusion?

A greater surface area increases the rate of diffusion due to more area for molecules to move in and out of the cell.

How does temperature affect diffusion?

Higher temperatures increase kinetic energy and the rate of chemical reactions, causing molecules to collide and interact more frequently.

How does concentration gradient affect diffusion?

A large difference in concentration between two areas leads to a steeper concentration gradient and a faster rate of diffusion.

Define Nucleoid.

A general region that is NOT membrane bound where genetic material is stored (Bacteria and Archaea).

Define Nucleus.

Membrane bound organelle that stores genetic material.

Define Cytoplasm.

Gelatinous liquid that fills the inside of a cell and includes various enzymes, salts, and organelles.

What is cell/plasma membrane?

Semipermable barrier that surronds all cells, seperating the cell’ s interior from the external environment and is made up of phospholipids

What are prokaryotes?

The simpliest organisms and primary fall into the categories of Archaea and Bacteria

What are eukaryotic cells?

Animals, plants, fungi, and protists are all eukaryotic. Eukaryotic cells are much more complex that prokaryotic cells.

What is the endomembrane system?

A network of interconnected membranes and organelles found in eukaryotic cells that work together to modify, package, and transport.

What is the function of the nucleus?

Respository of genetic information. In eukaryotes, DNA is linear and in prokaryotes it is singular and circular.

What is the function of Ribosomes?

Specalized organelles for protein synthesis and are found in all cell types in all three domains (enzymes are essential to life).

What is the function of Rough ER?

Attachment of ribosomes gives “ rough appearance ”. Functions for protein synthesis, folding, and modification.

What is the function of Smooth ER?

Relatively few bound organelles with functions for storage and synthesis of lipids.

What is the function of Golgi apparatus?

A network of flattened stacks of interconnected membranes (Golgi bodies) that primarly functions in the packagaing and distribution of molecules.

What is the function of Lysosomes?

Membrane bound digestive vesicles that arise from the golgi apparatus. Lysosomes contain enzymes that catalyze the necessary breakdown of macromolecules, forgein matter, and old organelles.

What is the function of Peroxisomes?

Enzyme bearing vesicles that play a vital role in detoxification of the cell and produce hydrogen peroxide as a by product.

What is the function of Vacuoles?

Membrane bound organelles that function for storage for nutrients, fluids, and materials and/or structural support.

What is the function of Mitochondria?

Membrane bound organelles that functions to produce ATP to fuel cell functions. Found in all eukaryotic cells.

What is the function of chloroplasts?

Specailized organelles found in plants and algea that are responsible for photosynthesis.

What is the endosymbiotic theory?

This theory proposes that some present day eukaryotic organelles evolved by a symbiosis between two free-living cells. Prokaryote was engulfed by another cell (eukaryotes precursor) and learned how to live symbiotically.

What is the function of Microfilaments?

Also known as actin filaments and are involved in cellula movement, structural support, and cell division. Support structural integrity by resisting compression and tension by external factors.

What is the function of Microtubules?

Provide structure, support, and allow for cell movement. Similar to actin filaments they resist compression. Essential for organizing and seperating chromosomes during mitosis and meiosis.

What is the function of Intermediate fibers?

Provide mechnical strength and stability for cells. Not directly involved in cell movement. Serve as structure framework to anchor organelles and maintian cell shape.

What is the function of Extracellular matrix?

Network of protein fibers that is found in all eukaryotic cells and helps support and structure the cell. A dynamic system (assembling and disassembling).

What are cell walls?

Present in plants, fungi, protists, bacteria, and archaea Eukaryotic cell walls are distinct from prokaryotic cell walls chemically and structurally.

What are Anchoring junctions?

Cell-to-cell connections that anchor neighboring cells together through interactions with the actin cytoskeleton. Allows for some ions through EX: epidermis

What are Tight junctions?

Specialized connections between adjacent animal cells that create a seal to prevent the passage of molecules and ions through the space between cells, maintaining distinct compartments within tissues. Allows for no movement EX: bladder

What are Gap junctions?

Channels that directly connect the cytoplasm of neighboring cells, allowing for the exchange of ions, nutrients, and signaling molecules to coordinate cellular activity. Allow for exchange

What are Plasmodesmata junctions?

Found in plant cells and allow for the connection of cytoplasm of adjoining cells. similar to gap junctions

Describe the Fluid mosiac model of cell membranes.

Mosiac of proteins floats in or on the fluid lipid bilayer like boats on a pond Saturated fatty acids make the membrane less fluid than unsaturated.

What are Integral membrane proteins?

Proteins that are permanently embedded within the lipid bilayer of cell membranes, often spanning the entire membrane. Their functions include transporting molecules across the membrane, acting as receptors for signaling, and helping maintain cell structure and communication.

What is the function of the cell’s internal protein network?

Supporting cell shape, anchoring membrane proteins, and helping transmit signals.

Why are cell surface proteins or glycoproteins important?

Identify the cell to other cells and play roles in immune recognition, communication, and tissue organization.

What is Passive transport?

Movement of molecules down their concentration gradient without the use of cellular energy, relying instead on diffusion or facilitated diffusion.

What is Active Transport?

Movement of molecules across a cell membrane against their concentration gradient using energy, usually in the form of ATP. Moving from low to high Agaisnt gradeint

What is Osmosis?

Passive movement of water molecules across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration.

Define Hypotonic.

A hypotonic solution indicates the solution has a lower concentration of solute compared to the cell. movement in to cell

Define Isotonic.

A isotonic solution indicates the solution has a equal concentration of solute comapred to the cell. no net movement

Define Hypertonic.

A hypertonic solution indicates the solution has a higher concentration of solute compared to the cell. movement out of the cell