Unit 1 Study Guide

What is the first step in conducting scientific inquiry?

Formulating and testing hypotheses.

What is a control group in an experiment?

A group in an experiment that receives no treatment and serves as a comparison baseline.

What is an Independent Variable (IV)?

The 'cause' factor in an experiment, intentionally manipulated by the researcher.

What is a Dependent Variable (DV)?

The 'effect' factor measured as a response to the independent variable's manipulation.

What does repeatability mean in scientific research?

The ability for other researchers to replicate observations and experiments with consistent results.

What makes a hypothesis testable?

It allows for empirical investigation to support or refute it.

What is a scientific theory?

A well-substantiated explanation for natural phenomena, supported by consistent evidence.

What defines an atom?

The smallest unit of matter that retains an element's properties.

What are the three main subatomic particles?

Protons, neutrons, and electrons.

What are Protons?

Positively charged particles found in the nucleus of an atom.

What are Neutrons?

Neutrally charged particles located in the nucleus of an atom.

What are Electrons?

Negatively charged particles that orbit around the nucleus.

What is an ion?

An atom with a positive or negative charge due to electron loss or gain.

What is a covalent bond?

A bond formed by the sharing of electron pairs between atoms.

What is a nonpolar covalent bond?

A bond where electrons are shared equally between atoms.

What is a polar covalent bond?

A bond where electrons are shared unevenly between atoms.

What is an ionic bond?

A bond resulting from the complete transfer of electrons between atoms.

What are hydrogen bonds?

Weaker attractions between a partially positive hydrogen atom and a negatively charged atom.

Why is water considered a polar molecule?

Due to polar covalent bonds between oxygen and hydrogen, creating partial charges.

What is the significance of ice being less dense than liquid water?

It allows ice to float, insulating aquatic environments and vital for aquatic life.

What role does water play as a solvent?

It dissolves hydrophilic substances, facilitating chemical reactions and transport in organisms.

What does the pH scale measure?

The acidity or basicity of a solution based on hydrogen ion concentration (H^+).

Why is pH important for organisms?

Extreme pH values can denature proteins and disrupt cellular functions.

What does tetravalent mean in relation to carbon?

Carbon can form four stable covalent bonds with other atoms.

What is a functional group in organic chemistry?

Groups that attach to carbon backbones and determine the molecule's chemical reactivity.

What is a monosaccharide?

The monomer of carbohydrates, such as glucose.

What are amino acids?

Monomers of proteins, each containing an amino group, a carboxyl group, and a variable R group.

What are triglycerides?

Fats and oils composed of glycerol and three fatty acids, used for energy storage.

What are phospholipids?

Molecules that form the core of cell membranes, with hydrophilic heads and hydrophobic tails.

What is the main function of nucleic acids?

To encode and transmit genetic information.

What are organelles?

Major intracellular structures within eukaryotic cells that perform specific functions.

What is the role of the ribosomes in the cell?

To synthesize proteins based on genetic instructions.

What is cytoplasm?

The fluid inside cells that contains organelles and is the site for many metabolic processes.

What is the function of the Golgi apparatus?

It modifies, sorts, and packages proteins and lipids for transport.

What defines the structure of biological membranes?

The Fluid Mosaic Model, consisting of a fluid bilayer of phospholipids.

What is selectively permeability in membranes?

The ability to control the movement of substances into and out of the cell.

What is osmosis?

The movement of water across a semi-permeable membrane from lower solute concentration to higher solute concentration.

What is diffusion?

The passive movement of substances down their concentration gradient without energy input.

What does primary active transport refer to?

The process that uses energy directly from ATP to move substances against their concentration gradient.

What is exocytosis?

The process of secreting substances from the cell by vesicles fusing with the plasma membrane.

What role do cilia and flagella play in cells?

They assist in cell movement and locomotion.

What is the function of microtubules in the cytoskeleton?

They help maintain cell shape and are important for cell division and intracellular transport.

What are the main characteristics of lipids?

Hydrophobic, nonpolar molecules that include triglycerides, phospholipids, and steroids.

What are the components of a nucleotide?

A phosphate group, a pentose sugar, and a nitrogenous base.

What are polypeptides?

Polymers formed from amino acids linked by peptide bonds.

What does the term 'dynamic instability' refer to in microtubules?

The cycles of growth and shrinkage in microtubules.

What role does cholesterol play in biological membranes?

It modulates membrane fluidity at different temperatures.

What is the central dogma of molecular biology?

The flow of genetic information from DNA to RNA to protein.

What is the function of lysosomes in eukaryotic cells?

To degrade damaged macromolecules and waste materials.

What is a plant cell's central vacuole?

A large organelle that stores water and nutrients and contributes to cell rigidity.

What is the primary component of a cell wall?

Cellulose in plants, providing structural support.

What is the key difference between rough ER and smooth ER?

Rough ER is involved in protein synthesis, while smooth ER is involved in lipid synthesis and detoxification.

What is the significance of plasmodesmata in plant cells?

They are channels that connect the cytoplasm of adjacent plant cells.

What are the key roles of the cytoskeleton?

Support the cell shape, enable movement of substances, and help in cell division.

What is the primary role of mitochondria?

ATP production through cellular respiration.