UNC BIOL 101 Quiz 1 (Lesson 1 - 3)
Term: Biology
Definition: The scientific study of life, exploring the characteristics and behaviors of living organisms.
Term: Characteristics of Life
Definition: Properties and processes that living things exhibit, such as regulating internal environments, taking in and using energy, and responding to environmental stimuli. Cells are the fundamental units of life, capable of reproduction, growth, and repair.
Term: Diversity of Life
Definition: The wide range of organisms, from single-celled bacteria to complex multicellular organisms, highlighting the variation in life forms.
Term: Hierarchy of Biological Organization
Definition: The structural levels of organization in life, from molecules to the entire biosphere, with each level providing new emergent properties.
Term: Emergent Properties
Definition: Complex characteristics that arise from the specific arrangement and interactions of components at a certain level of biological organization, not present at lower levels.
Term: Scientific Inquiry
Definition: The approach to understanding the natural world through observation, data collection, hypothesis formation, and experimentation.
Term: Hypothesis
Definition: A proposed explanation for a set of observations that leads to predictions that can be tested through further observations or experiments.
Term: Controlled Experiment
Definition: A scientific test where one variable (independent variable) is manipulated to observe its effect on another variable (dependent variable), with results compared to a control group.
Term: Scientific Theory
Definition: A broad explanation supported by a large body of evidence, uncontradicted by scientific data, such as the theory of evolution by natural selection.
Term: Qualitative Data
Definition: Descriptive information gathered through observations, such as behavioral recordings.
Term: Quantitative Data
Definition: Numerical measurements that can be analyzed statistically.
Term: Clinical Trials
Definition: Controlled experiments involving human subjects, often using placebos and double-blind procedures to avoid bias.
Term: Observational Studies
Definition: Studies analyzing data without manipulating the environment or subjects, including retrospective and prospective studies.
Term: Emergence
Definition: The concept that new properties and complexities arise from interactions among simpler elements in biological systems.
Term: Camouflage Hypothesis
Definition: The hypothesis that animal color patterns evolved as adaptations to protect them from predation, tested by comparing predation rates on camouflaged versus non-camouflaged models.
Term: Red Panda Classification
Definition: The use of DNA comparisons to determine the evolutionary relationships of the red panda, leading to its classification in the family Ailuridae.
Term: Nonlinear Nature of Science
Definition: The idea that the scientific process is dynamic and flexible, involving iterative steps rather than a rigid sequence.
Term: Scientific Collaboration
Definition: The practice of scientists working together, sharing data and methods, and reviewing each other’s work to advance understanding and improve research quality.
Term: Darwin’s Theory of Evolution
Definition: The theory proposed by Charles Darwin that species evolve through "descent with modification," driven by natural selection based on variation, overproduction of offspring, and survival of the fittest.
Term: Tree of Life
Definition: A metaphorical tree representing the evolutionary relationships among species, tracing back to common ancestors.
Term: Evidence for Evolution
Definition: Support for the theory of evolution provided by the fossil record, experiments, observations, and DNA comparisons.
Term: Carbon's Versatility
Definition: Carbon atoms form the backbone of most biological molecules due to their ability to form four covalent bonds, allowing for large and complex molecular structures.
Term: Organic Compounds
Definition: Molecules containing carbon, usually bonded with hydrogen, which are integral to life.
Term: Molecular Shapes
Definition: The shape of a molecule, influenced by carbon bonding, typically determines its function.
Term: Carbon Skeleton Variations
Definition: Variations in carbon chains, including length, branching, double bonds, or ring formation, contribute to the diversity of organic molecules.
Term: Isomers
Definition: Molecules with the same molecular formula but different structures, leading to different properties and biological functions.
Term: Hydrocarbons
Definition: Molecules consisting solely of carbon and hydrogen. Though rare in living organisms, they are a key component of fats and provide energy.
Term: Functional Groups
Definition: Specific groups of atoms attached to carbon backbones that affect molecular function. Most are polar and hydrophilic, aiding solubility in water.
Term: Hydroxyl Group (-OH)
Definition: Found in alcohols like ethanol, it is a functional group that contributes to molecule polarity.
Term: Carbonyl Group (C=O)
Definition: Present in sugars, can be within or at the end of carbon chains, influencing molecular reactivity.
Term: Carboxyl Group (-COOH)
Definition: Acts as an acid by contributing H+ ions to solutions, found in amino acids.
Term: Amino Group (-NH2)
Definition: Acts as a base by picking up H+ ions, present in amino acids.
Term: Phosphate Group (-PO4)
Definition: Involved in energy transfers, as in ATP.
Term: Methyl Group (-CH3)
Definition: Nonpolar group affecting molecular shape and function.
Term: Macromolecules
Definition: Large biological molecules such as carbohydrates, lipids, proteins, and nucleic acids, most of which are polymers made from monomers.
Term: Polymer Formation
Definition: The process of creating polymers through dehydration reactions where water is removed as monomers bond.
Term: Polymer Breakdown
Definition: The process of breaking down polymers via hydrolysis, where water is added to break bonds between monomers.
Term: Enzymes
Definition: Proteins that facilitate the formation and breakdown of polymers.
Term: Monosaccharides
Definition: The simplest form of carbohydrates, such as glucose and fructose, serving as energy sources and building blocks for larger molecules.
Term: Disaccharides
Definition: Carbohydrates formed by joining two monosaccharides via a dehydration reaction. Common examples include maltose and sucrose.
Term: High Sugar Consumption
Definition: Linked to health problems like cardiovascular disease, high blood pressure, and diabetes, and includes recommendations to limit daily sugar intake and improve food labeling.
Term: Polysaccharides
Definition: Long chains of monosaccharides linked by dehydration reactions, serving as storage molecules or structural compounds. Examples include starch, glycogen, cellulose, and chitin.
Term: Starch
Definition: A storage polysaccharide in plants made of glucose monomers, serving as an energy reserve.
Term: Glycogen
Definition: A storage polysaccharide in animals, more branched than starch, stored in liver and muscle cells.
Term: Cellulose
Definition: A major component of plant cell walls, composed of glucose with different linkages forming strong microfibrils. Aids in digestive health as insoluble fiber.
Term: Chitin
Definition: A structural polysaccharide in insects, crustaceans, and fungi, used to build exoskeletons and cell walls.
Term: Fats
Definition: Lipids made of glycerol and fatty acids, used primarily for energy storage. They are hydrophobic.
Term: Saturated Fats
Definition: Fats with no double bonds in fatty acid chains, solid at room temperature (e.g., animal fats).
Term: Unsaturated Fats
Definition: Fats with one or more double bonds, liquid at room temperature (e.g., vegetable oils).
Term: Hydrogenation
Definition: The process of adding hydrogen to unsaturated fats to make them solid, creating trans fats associated with health risks.
Term: Phospholipids
Definition: Key components of cell membranes, with a hydrophilic phosphate head and two hydrophobic fatty acid tails, forming a bilayer.
Term: Steroids
Definition: Lipids with a four-ring structure, such as cholesterol, which is part of cell membranes and a precursor for other steroids.
Term: Proteins
Definition: Polymers of amino acids with diverse functions including enzymes, transporters, and structural components.
Term: Primary Structure of Proteins
Definition: The sequence of amino acids in a polypeptide chain.
Term: Secondary Structure of Proteins
Definition: Local folding patterns such as alpha helices and beta sheets.
Term: Tertiary Structure of Proteins
Definition: The overall 3D shape of a single polypeptide chain.
Term: Quaternary Structure of Proteins
Definition: The arrangement of multiple polypeptide chains in a protein.
Term: Denaturation
Definition: The process where proteins lose their functional shape due to factors like heat, disrupting their structure and function.
Term: Amino Acids
Definition: The building blocks of proteins, linked by peptide bonds. They can be hydrophobic or hydrophilic, influencing protein structure and function.
Term: DNA
Definition: Contains genetic instructions for protein synthesis and replication, forming a double helix with complementary base pairing (A-T, C-G).
Term: RNA
Definition: Translates genetic information from DNA into proteins.
Term: Gene Expression
Definition: The process where DNA is transcribed into RNA, which is then translated into proteins.
Term: Lactase Persistence
Definition: The ability to digest lactose into adulthood, evolved in response to the domestication of dairy animals, with mutations allowing continued lactase production.
Cell Size and Function
Definition: Cells need to be large enough to house essential components but are typically small to maximize efficiency in material exchange across the plasma membrane.
Surface-to-Volume Ratio
Definition: Smaller cells have a larger surface area relative to their volume, which enhances the efficiency of material exchange. Example: 27 small cubes have three times the surface area of one large cube with the same total volume.
Plasma Membrane Structure
Definition: The plasma membrane is composed of a phospholipid bilayer with hydrophilic heads facing outward and hydrophobic tails facing inward. This structure forms a flexible boundary between the cell and its environment.
Membrane Proteins
Definition: Proteins embedded in the phospholipid bilayer that can form channels or act as pumps to transport molecules into or out of the cell.
Prokaryotic Cells
Definition: Smaller, simpler cells lacking a membrane-enclosed nucleus and membrane-enclosed organelles. DNA is coiled in a nucleoid region.
Eukaryotic Cells
Definition: Larger, more complex cells with a membrane-enclosed nucleus and various membrane-enclosed organelles.
Nucleus
Definition: The membrane-enclosed organelle that houses most of the cell's DNA and controls genetic activities.
Chromatin
Definition: A diffuse mass of DNA and proteins when the cell is not dividing, which condenses into visible chromosomes during cell division.
Nuclear Envelope
Definition: A double membrane with two phospholipid bilayers that controls material flow in and out of the nucleus through protein-lined pores.
Nucleolus
Definition: The structure within the nucleus that synthesizes ribosomal RNA (rRNA) and assembles ribosomal subunits.
Ribosomes
Definition: Cellular structures that synthesize proteins using instructions from messenger RNA (mRNA). They can be free in the cytosol or bound to the endoplasmic reticulum.
Endoplasmic Reticulum (ER)
Definition: A major cellular manufacturing and processing center with two regions:
Smooth ER: Involved in lipid synthesis, detoxification, and calcium storage.
Rough ER: Studded with ribosomes, involved in protein synthesis and modification.
Lysosomes
Definition: Membrane-enclosed sacs containing digestive enzymes that break down various substances within the cell.
Peroxisomes
Definition: Organelles involved in fatty acid breakdown and detoxification, converting toxic hydrogen peroxide (H₂O₂) into water.
Mitochondria
Definition: Organelles that carry out cellular respiration, converting chemical energy from food into ATP. They have an outer membrane, inner membrane with cristae, and a matrix containing DNA and enzymes.
Chloroplasts
Definition: Organelles in plant cells that convert solar energy into chemical energy through photosynthesis. They contain thylakoids where chlorophyll captures solar energy.
Endosymbiont Theory
Definition: The theory that mitochondria and chloroplasts originated from prokaryotes engulfed by larger cells, establishing a symbiotic relationship.
Cytoskeleton
Definition: A network of protein fibers providing structural support, movement, and shape to the cell. Components include:
Microtubules: Support cell shape, transport, and cell division.
Intermediate Filaments: Reinforce cell shape and anchor organelles.
Microfilaments (Actin Filaments): Support cell shape and facilitate movement.