1406 Study Guide Exam 1 (1)

Cytoskeleton

Includes microfilaments, intermediate filaments, and microtubules; important for maintenance of cell shape, movement of organelles, amoeboid movement, and muscle contraction.

Mitochondria

Site of cellular respiration in eukaryotic cells; highest in quantity in metabolically active cells.

Chloroplast

Site of photosynthesis in eukaryotic plant cells.

Plasma Membrane

Phospholipid bilayer with embedded proteins (channels) found in all cells.

Ribosomes

Free or bound to Endoplasmic Reticulum; responsible for protein synthesis and translation.

Endoplasmic Reticulum

Connected to the nucleus; has rough (covered with ribosomes) and smooth portions; involved in synthesizing materials necessary for cell function.

Lysosome

Houses enzymes that break down ingested substances and damaged organelles.

Golgi Apparatus

Stacks of sacs where products of the Endoplasmic Reticulum are processed and sent to other organelles or the cell surface.

Nucleus

Houses the cell’s DNA, which directs protein synthesis via messenger RNA.

Nucleolus

Site where subunits of ribosomes are assembled.

Vacuole

Organelle with various functions including storage, transport, and maintaining environmental stability.

Peroxisome

Involved in metabolic processes, particularly breaking down hydrogen peroxide; does not originate from the endomembrane system.

Cilia

Locomotor appendages made of microtubules in a “9 + 2” arrangement; move like rowing team oars.

Flagella

Locomotor appendages made of microtubules in a “9 + 2” arrangement; longer than cilia and move with a whip-like motion.

Levels of Organization

The 10 levels from smallest to largest: molecules, organelles, cells, tissues, organs/organ systems, organisms, populations, communities, ecosystems, biosphere.

Control Experiment

An experiment designed to provide a basis of comparison for the experimental group.

Independent Variable

The factor that is changed or tested in an experiment.

Dependent Variable

The measure used to judge the outcome of an experiment; depends on the independent variable.

Mitochondria vs Chloroplasts

Mitochondria are involved in cellular respiration found in all eukaryotic cells, while chloroplasts are involved in photosynthesis found in eukaryotic plant cells.

Endomembrane System

Includes Endoplasmic reticulum, Golgi apparatus, vacuoles, and lysosomes; peroxisomes are not part of this system.

Contractile Vacuoles

Important for collecting and expelling excess water to maintain osmoregulation and prevent bursting.

Differences between Plant and Animal Cells

Plant cells have chloroplasts and a cell wall, while animal cells do not; plant cells have a large centralized vacuole, animal cells have smaller vacuoles.

Polysaccharides examples

Include starch and glycogen for storage; cellulose in plant cell walls and chitin in insect/crustacean/fungal cell walls.

Saturated vs Unsaturated Lipids

Saturated fats have the maximum number of hydrogens with only single bonds between carbons; unsaturated fats have at least one double bond, not at maximum hydrogens.

Hydrophobic Fats

Fats are considered hydrophobic due to nonpolar fatty acid chains that do not interact with polar water.

Four Structural Components of Amino Acid

Central carbon, bonded hydrogen, bonded amino group, bonded carboxyl group, bonded R group which determines properties.

Examples of Lipids

Include phospholipids, steroids, and cholesterol.

Four Structures of Proteins

Primary (sequence of amino acids), Secondary (coil or fold; alpha helix or beta pleated sheet), Tertiary (3D shape from R group interactions), Quaternary (multiple polypeptides joined together).

Functional Chemical Groups

Include Hydroxyl (OH), Carboxyl (COOH), Phosphate (OPO3), Carbonyl (C=O), Amino (NH2), Methyl (CH3).

Types of Chemical Bonds

From strongest to weakest: Covalent, Polar covalent, Nonpolar covalent, Ionic, and Hydrogen bonds.

Element

Pure substance made of one type of atom, cannot be broken down into smaller components.

Compound

Two or more elements in a fixed ratio; can be broken down into smaller parts.

Monomer

Building blocks of polymers.

Polymer

Made of monomers; also known as macromolecules such as proteins, nucleic acids, polysaccharides, and lipids.

Trans Fat

Fat resulting from taking relatively healthy unsaturated fat and undergoing hydrogenation to create synthesized saturated fat.

Matter

All things made of matter, which has mass and consists of elements.

Electron

Negatively charged subatomic particle located outside of the nucleus; outermost ones determine reactivity of the atom.

Proton

Positively charged subatomic particle located inside the nucleus; determines the identity of the atom.

Neutron

Neutrally charged subatomic particle located inside the nucleus; contributes to half the mass of the atom.

Electronegativity

An atom's tendency to attract and hold on to electrons.

Enzyme

A protein that speeds up a chemical reaction by lowering the activation energy.

Protein

Made of amino acids.

Carbohydrate

Sugars and starches; general formula of CH2O.

Nucleotide

Building blocks of DNA and RNA, composed of a phosphate group, sugar, and nitrogenous base.

Lipid

Fats or triglycerides; hydrophobic; used for energy storage.

Valence Electron

Outermost electrons that determine an element's reactivity; stable elements have 2, 8, and 8 electrons in their outer levels.

Subatomic Particles

Protons and neutrons determine mass; protons determine identity; electrons determine overall charge.

Chemical Equation

Process of breaking and forming chemical bonds; reflects the law of conservation of mass.

Dehydration Synthesis Reaction

Occurs when monomers join to form larger polymers.

Hydrolysis Reaction

Occurs when large polymers are broken down into smaller monomers.

Denature a Protein

To change the structure of a protein, often through changes in pH or temperature.

Structure and Function

Structure determines function; changing the structure can lead to loss of function.

Lactose Tolerance and Evolution

Some people can tolerate lactose due to mutations that allow continuous production of the lactase enzyme, beneficial for ancestors reliant on dairy.