Biology Exam 1: Cell Structure, Molecular Biology, and Scientific Principles

What is biology?

The study of life and living organisms.

How does technology differ from science?

Technology applies scientific knowledge for practical purposes, while science seeks to understand natural phenomena.

What processes are responsible for life?

Processes include metabolism, growth, reproduction, and response to stimuli.

What is homeostasis?

The maintenance of stable internal conditions in an organism.

What are the levels of organization of living things?

Levels include cells, tissues, organs, organ systems, and organisms.

Name five different theories in science.

Examples include the theory of evolution, cell theory, germ theory, atomic theory, and the theory of relativity.

What experiments did Louis Pasteur and Francisco Redi conduct?

Both experiments demonstrated that life does not arise spontaneously from non-living matter.

What are the main features of the scientific method?

Features include observation, hypothesis formulation, experimentation, analysis, and conclusion.

Differentiate between inductive and deductive reasoning.

Inductive reasoning involves drawing general conclusions from specific observations, while deductive reasoning starts with general principles to predict specific outcomes.

What is the difference between a hypothesis and a theory?

A hypothesis is a testable prediction, while a theory is a well-substantiated explanation based on a body of evidence.

What is the central dogma of genetics/molecular biology?

The central dogma describes the flow of genetic information from DNA to RNA to protein.

What are the first and second laws of thermodynamics?

The first law states that energy cannot be created or destroyed; the second law states that entropy in a closed system tends to increase.

Define taxonomy and its supporting terms.

Taxonomy is the science of classification; supporting terms include classification (grouping), nomenclature (naming), and identification (recognizing).

What are the properties of atoms?

Atoms consist of protons, neutrons, and electrons, with relationships defining their structure and behavior.

What are elements and how are isotopes formed?

Elements are pure substances made of one type of atom; isotopes are variants of elements with the same number of protons but different numbers of neutrons.

What is the difference between atomic number, mass number, and atomic weight?

Atomic number is the number of protons, mass number is the total number of protons and neutrons, and atomic weight is the average mass of an element's isotopes.

Describe the structure of water.

Water is a polar molecule with two hydrogen atoms covalently bonded to one oxygen atom.

What are electron orbitals and energy shells?

Electron orbitals are regions where electrons are likely to be found, while energy shells are layers of orbitals at different energy levels.

How do elements form chemical bonds?

Elements form bonds by sharing or transferring electrons to achieve stable electron configurations.

What is the relationship among an atom, molecule, and compound?

An atom is the smallest unit of an element, a molecule is two or more atoms bonded together, and a compound is a molecule that contains at least two different elements.

What are the differences between covalent, ionic, and hydrogen bonds?

Covalent bonds involve sharing electrons, ionic bonds involve the transfer of electrons, and hydrogen bonds are weak attractions between polar molecules.

What is ionization and the difference between anions and cations?

Ionization is the process of forming ions; anions are negatively charged ions, while cations are positively charged ions.

What are the different types of reactions?

Types include synthesis (combining), hydrolysis (breaking down with water), and others.

What are solutes and solvents?

Solutes are substances dissolved in a solvent, which is the medium that dissolves the solute.

Differentiate between hydrophilic, hydrophobic, and amphipathic substances.

Hydrophilic substances are water-attracting, hydrophobic substances repel water, and amphipathic substances have both hydrophilic and hydrophobic parts.

Describe the pH scale and define acid, base, and neutral levels.

The pH scale measures acidity or alkalinity; acids have a pH less than 7, bases have a pH greater than 7, and neutral solutions have a pH of 7.

What is the difference between inorganic and organic compounds?

Inorganic compounds typically lack carbon-hydrogen bonds, while organic compounds contain them.

What are functional groups?

Functional groups are specific groups of atoms within molecules that determine the chemical properties of those molecules.

What are macromolecules and monomers?

Macromolecules are large complex molecules made of smaller units called monomers.

Define a carbohydrate.

Carbohydrates are organic compounds made of carbon, hydrogen, and oxygen, typically in a ratio of 1:2:1.

What are mono-, di-, and polysaccharides?

Monosaccharides are single sugar units, disaccharides are two sugar units, and polysaccharides are long chains of sugar units.

What are the general functions of carbohydrates in cells?

Carbohydrates provide energy, serve as structural components, and are involved in cell signaling.

Identify the types of lipids.

Types include triglycerides, phospholipids, fatty acids, and cholesterol.

Describe the structure of amino acids.

Amino acids consist of a central carbon atom, an amino group, a carboxyl group, a hydrogen atom, and a variable R group.

What are nucleic acids and the differences between DNA and RNA?

Nucleic acids store and transmit genetic information; DNA is double-stranded and contains thymine, while RNA is single-stranded and contains uracil.

What are the general parts of a cell?

Parts include the plasma membrane, cytoplasm, organelles, and nucleus.

What are the four main functions of cells?

Functions include metabolism, energy production, synthesis of molecules, and response to environmental changes.

What types of microscopes are used to study cells?

Types include light microscopes, electron microscopes, and fluorescence microscopes.

What is the structure and function of the plasma membrane?

The plasma membrane is a lipid bilayer with embedded proteins that regulates the passage of materials in and out of the cell.

Why is a membrane potential formed?

A membrane potential is formed due to differences in ion concentration across the plasma membrane.

What are the functions of membrane lipids?

Membrane lipids provide structural integrity, facilitate cell signaling, and form barriers.

What is the fluid-mosaic model of membrane structure?

The fluid-mosaic model describes the plasma membrane as a flexible structure with various proteins floating in or on the fluid lipid bilayer.

What are the functions of membrane proteins?

Membrane proteins facilitate transport, act as receptors, and provide structural support.

What are transport proteins?

Transport proteins assist in the movement of molecules across the plasma membrane.

How can molecules and ions pass through the plasma membrane?

Molecules can pass through via simple diffusion, facilitated diffusion, or active transport.

What is diffusion and how does it relate to concentration gradients?

Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration.

What is osmosis and osmotic pressure?

Osmosis is the diffusion of water across a semipermeable membrane, and osmotic pressure is the pressure required to prevent water movement.

What are hypotonic, isotonic, and hypertonic solutions?

Hypotonic solutions have lower solute concentration than the cell, isotonic solutions have equal solute concentration, and hypertonic solutions have higher solute concentration.

What is mediated transport?

Mediated transport involves the use of proteins to facilitate the movement of substances across the membrane.

Compare facilitated diffusion, primary active transport, and secondary active transport.

Facilitated diffusion moves substances down their concentration gradient without energy, primary active transport uses energy to move substances against their gradient, and secondary active transport uses the energy from primary transport to move other substances.