Test 1 Study Guide: The Science of Biology to Lipids

Flashcards covering key biology concepts from the science of life through basic macromolecules, based on the provided notes.

What is Biology?

The study of living things.

What are the seven characteristics of living systems?

Cellular organization; ordered complexity; sensitivity; growth, development, and reproduction; energy utilization; homeostasis; evolutionary adaptation.

Describe the hierarchical organization in biology from the cellular level to the biosphere.

Cellular level: atoms, molecules, organelles, cells; Organismal level: tissues, organs, organ systems; Population level: population, community; Ecosystem level; Biosphere.

What are emergent properties?

Properties that arise at higher levels of organization and are not present in the components alone.

What is inductive reasoning?

Specific observations leading to general conclusions.

What is deductive reasoning?

General principles leading to specific predictions.

What is descriptive science?

Science that describes natural phenomena without manipulating variables.

What is hypothesis-driven science?

Science that tests hypotheses with experiments and predictions.

What is a scientific theory?

A well-supported, repeatedly tested explanation of natural phenomena.

What is basic vs applied research?

Basic research aims to expand knowledge; applied research aims to solve practical problems.

Describe Darwin’s theory of evolution by natural selection.

Evolution by natural selection: differential survival and reproduction due to heritable variation.

What is natural selection?

Differential survival and reproduction due to heritable variation.

What does the fossil record show as evidence for natural selection?

Patterns of change over time documenting descent with modification.

How does Earth's age support evolution?

Long timescales allow gradual accumulation of heritable changes.

What is meant by the 'mechanism for heredity' as evidence for evolution?

Genetic inheritance provides the variation that natural selection acts upon.

Differentiate homologous structures from analogous structures.

Homologous structures share a common ancestry; analogous structures have similar function but different ancestry.

What does molecular evidence for evolution include?

DNA and protein sequence similarities reflecting evolutionary relationships.

What are core concepts in biology related to laws, structure, energy, information, and evolution?

Life obeys chemical/physical laws; structure determines function; living systems transform energy and matter; information transactions (DNA/cell processes); evolution explains unity and diversity.

What do homeodomain proteins illustrate in biology?

Evolutionary unity and diversification of development across organisms.

What are the four major elements found in living systems?

Carbon, hydrogen, oxygen, and nitrogen.

Define atomic number.

The number of protons in an atom's nucleus.

Define atomic mass.

Total number of protons and neutrons in the nucleus.

What is an ion? Distinguish cations and anions.

An ion is an atom with a net electric charge; cations are positively charged, anions are negatively charged.

What are isotopes?

Variants of an element with different numbers of neutrons; some are radioactive with a half-life.

What are electron orbitals and energy levels?

Regions around the nucleus where electrons reside, organized into energy levels.

What are valence electrons and the octet rule?

Valence electrons determine bonding; atoms tend to complete an octet of eight electrons in their outer shell.

Define an ionic bond.

Electrostatic attraction between oppositely charged ions.

Differentiate polar and nonpolar covalent bonds.

Covalent bonds with unequal electron sharing are polar; equal sharing is nonpolar.

What are reactants and products in a chemical reaction?

Reactants are starting substances; products are substances formed.

Name three factors that influence the rate of chemical reactions.

Temperature; concentration; catalysts.

Explain water's polarity and hydrogen bonding.

Water is a polar molecule; hydrogen bonds form between a hydrogen atom and an electronegative atom like oxygen.

What is cohesion and what is surface tension?

Cohesion is attraction between like molecules; surface tension is the cohesive force at a liquid's surface.

What is adhesion and capillary action?

Adhesion is attraction between water and surfaces; capillary action is movement of water in narrow spaces due to adhesion and cohesion.

List key properties of water (Table 2.3).

High specific heat; high heat of vaporization; solid water is less dense than liquid; good solvent; organizes nonpolar molecules; can form ions.

Why is water a good solvent?

Because of its polarity, it dissolves many ionic and polar compounds.

What is pH and what do acids and bases mean?

pH is a measure of hydrogen ion concentration; acids release H+, bases accept H+.

What are buffers?

Substances that minimize pH changes by neutralizing added acids or bases.

What is the carbon framework of biological molecules?

Carbon forms the backbone of organic molecules, capable of forming up to four covalent bonds.

What are functional groups?

Specific groupings of atoms that impart characteristic properties to organic molecules.

What are isomers and the difference between structural and stereoisomers?

Isomers have same formula but different structures; structural isomers differ in connectivity; stereoisomers differ in spatial arrangement.

What does it mean for a molecule to be chiral?

A molecule that is not superimposable on its mirror image.

What are the four main biomolecules?

Carbohydrates, nucleic acids, proteins, lipids.

What is dehydration synthesis?

A reaction that links monomers by removing water.

What is hydrolysis?

A reaction that breaks polymers by adding water.

What is the relationship between carbohydrates' monomers and polymers?

Monosaccharides are monomers; polysaccharides are polymers.

Name examples of monosaccharides.

Glucose and fructose (also galactose).

Name examples of disaccharides.

Sucrose, lactose, maltose.

Name examples of polysaccharides.

Starch, glycogen, cellulose, chitin.

What are nucleic acids, and what are their monomer and polymer?

Nucleic acids store genetic information; monomers are nucleotides; polymers are DNA and RNA.

What are nucleotides composed of?

A sugar, a phosphate, and a nitrogenous base.

What are the five nitrogenous bases?

Adenine (A), Guanine (G), Thymine (T), Cytosine (C), Uracil (U).

What are phosphodiester bonds?

Covalent bonds that connect nucleotides in DNA/RNA by linking the sugar to phosphate groups.

What is the function of DNA and the base-pairing rules in DNA?

DNA stores genetic information; A pairs with T, G with C.

What is the function of RNA?

RNA transfers genetic information and mediates protein synthesis; uses U instead of T.

What are amino acids?

Amino acids are the monomers of proteins; they have a central carbon, amino group, carboxyl group, hydrogen, and an R group.

What are peptide bonds?

Covalent bonds formed between amino acids via dehydration synthesis.

What are the four levels of protein structure?

Primary, secondary, tertiary, and quaternary structures.

What are chaperones?

Molecules that assist in proper protein folding.

What is protein denaturation?

Loss of protein 3D structure and function due to heat, pH, or chemicals.

What are lipids and their solubility characteristics?

Lipids are hydrophobic and insoluble in water.

What are fats composed of?

A glycerol backbone attached to three fatty acids.

What are fatty acids and how do saturated vs. unsaturated fats differ?

Fatty acids are carboxylic acids; saturated fats have no double bonds, unsaturated fats have one or more double bonds.

What are phospholipids?

Lipids with glycerol, two fatty acid tails, and a phosphate-containing head.

What are micelles and the phospholipid bilayer?

Micelles are single-layer lipid assemblies; phospholipid bilayers form membranes with two layers.

What is the difference between a micelle and a phospholipid bilayer?

Micelles are spherical single-layer structures; bilayers form two-layer membranes.