AP exam 1

What is the basic structural and functional unit of life?

The cell

What does organismal activity depend on?

Individual and collective activity of cells

What dictates the biochemical activities of cells?

Subcellular structure

What is the basis for the continuity of life?

Cellular basis

What separates intracellular fluids from extracellular fluids?

Plasma membrane

What is glycocalyx?

A glycoprotein area that provides specific biological markers for cell recognition.

What is the Fluid Mosaic Model?

A model describing the double bilayer of lipids with embedded proteins in the plasma membrane.

What components make up the bilayer in the Fluid Mosaic Model?

Phospholipids, cholesterol, and glycolipids.

What are glycolipids?

Lipids with bound carbohydrates.

What are the two types of bipoles in phospholipids?

Hydrophobic and hydrophilic.

What are the functions of membrane proteins?

Transport, enzymatic activity, signal transduction, intercellular adhesion, cell-cell recognition, and attachment to cytoskeleton and extracellular matrix.

What is a transport protein?

A type of membrane protein that facilitates the movement of substances across the membrane.

What is the role of receptor proteins?

They are involved in signal transduction.

What is the function of structural proteins in the membrane?

They provide intercellular adhesion and attachment to the cytoskeleton and extracellular matrix.

What pathology is associated with a problem in protein function?

Cystic Fibrosis

What is the function of the nucleus in a cell?

It houses the cell's genetic material and controls cellular activities.

What is the role of ribosomes in a cell?

They are responsible for protein synthesis.

What is the function of lysosomes?

They contain enzymes for digestion and waste processing.

What is the role of mitochondria?

They produce energy (ATP) through cellular respiration.

What are microtubules and microfilaments?

Components of the cytoskeleton that provide structure and shape to the cell.

What is CFTR?

a chloride ion channel.

What is the genetic basis of CFTR mutation?

It is a recessive mutation where 1 of 508 amino acids is changed or missing.

What are the consequences of CFTR mutation?

Results in thick mucous in airways, salty sweat, and blocked pancreatic ducts.

What health issues arise from thick mucous in airways?

Leads to frequent infections.

How does pancreas malfunction due to CFTR affect health?

It leads to malnutrition and potential diabetes.

What is the impact of CFTR mutation on life expectancy?

It results in reduced life expectancy.

What are the main components of plasma membrane surfaces?

They differ in the kind and amount of lipids, with glycolipids found only in the outer membrane surface.

What percentage of membrane lipid is cholesterol?

20% of all membrane lipid is cholesterol.

What are lipid rafts?

composed of sphingolipids and cholesterol.

What is the function of lipid rafts?

concentrating platforms for cell-signaling molecules.

What is a tight junction?

impermeable junction that encircles the cell.

What is a desmosome?

anchoring junction scattered along the sides of cells.

What is a gap junction?

nexus that allows chemical substances to pass between cells

simple diffusion

The natural movement of nonpolar and lipid-soluble substances from areas of high concentration to low concentration

What is facilitated diffusion?

The transport of glucose, amino acids, and ions through carrier proteins or protein channels.

What are carrier proteins?

Integral transmembrane proteins that show specificity for certain polar molecules, including sugars and amino acids.

What is osmosis?

The diffusion of water across a semipermeable membrane.

What is osmolarity?

The total concentration of solute particles in a solution.

What is tonicity?

How a solution affects cell volume.

What is an isotonic solution?

A solution with the same solute concentration as that of the cytosol.

What is a hypertonic solution?

A solution having a greater solute concentration than that of the cytosol.

What is a hypotonic solution?

A solution having a lesser solute concentration than that of the cytosol.

What is passive membrane transport?

The movement of substances across a membrane without the use of energy.

What is active transport?

The movement of solutes across a membrane using ATP and carrier proteins, moving against the concentration gradient.

What drives filtration in passive membrane transport?

The passage of water and solutes through a membrane by hydrostatic pressure.

What stimulates phosphorylation of the pump protein in the sodium-potassium pump?

Binding of cytoplasmic Na+ to the pump protein.

What molecule provides the phosphate group for phosphorylation in the sodium-potassium pump?

ATP.

What happens to the pump protein after phosphorylation?

It changes its shape.

What is expelled from the cell as a result of the shape change in the sodium-potassium pump?

Na+ (sodium ions).

What binds to the pump protein after Na+ is expelled?

Extracellular K+ (potassium ions).

What triggers the release of the phosphate group from the pump protein?

K+ binding.

What restores the original conformation of the pump protein?

Loss of phosphate.

What are the concentration gradients maintained by the sodium-potassium pump?

High Na+ concentration outside the cell and high K+ concentration inside the cell.

What is the primary function of the sodium-potassium pump?

To maintain the electrochemical gradient across the cell membrane.

How many Na+ ions are typically expelled for every K+ ion brought into the cell by the pump?

Three Na+ ions are expelled for every two K+ ions brought in.

What is a symport system?

A transport mechanism where two substances are moved across a membrane in the same direction.

What is an antiport system?

A transport mechanism where two substances are moved across a membrane in opposite directions.

What is primary active transport?

A process that involves the hydrolysis of ATP to phosphorylate the transport protein, causing a conformational change.

What is secondary active transport?

A process that uses an exchange pump, such as the Na+-K+ pump, to indirectly drive the transport of other solutes.

What is vesicular transport?

The transport of large particles and macromolecules across plasma membranes.

What is exocytosis?

A process that moves substances from the cell interior to the extracellular space.

What is endocytosis?

A process that enables large particles and macromolecules to enter the cell.

What is transcytosis?

The process of moving substances into, across, and then out of a cell.

What is vesicular trafficking?

The movement of substances from one area in the cell to another.

What is phagocytosis?

A process where pseudopods engulf solids and bring them into the cell's interior.

What is fluid-phase endocytosis?

A process where the plasma membrane infolds, bringing extracellular fluid and solutes into the cell.

What is receptor-mediated endocytosis?

A process where clathrin-coated pits provide the main route for endocytosis and transcytosis.

What are non-clathrin-coated vesicles?

Caveolae that serve as platforms for a variety of signaling molecules.

What is the resting membrane potential?

The point where K+ potential is balanced by the membrane potential, ranging from -20 to -200 mV.

What are cell adhesion molecules (CAMs)?

Proteins that anchor cells to the extracellular matrix and assist in cell movement and immune response.

What is contact signaling?

A form of signaling important in normal development and immunity.

What is electrical signaling?

Signaling that involves voltage-regulated ion gates in nerve and muscle tissue.

What is chemical signaling?

A process where neurotransmitters bind to chemically gated channel-linked receptors.

What is the role of G protein-linked receptors?

They activate a G protein upon ligand binding, which then causes the release of a second messenger.

What is the function of mitochondria?

To provide most of the cell's ATP via aerobic cellular respiration and contain their own DNA and RNA.

What is the rough endoplasmic reticulum (ER)?

A type of ER with ribosomes on its surface, responsible for manufacturing secreted proteins and integral membrane proteins.

What is the smooth endoplasmic reticulum (ER)?

A type of ER involved in lipid metabolism, detoxification, and calcium storage.

What is the Golgi apparatus?

A stacked structure that modifies, concentrates, and packages proteins for secretion or delivery to other organelles.

What are lysosomes?

Membranous bags containing digestive enzymes that digest ingested bacteria, viruses, and toxins.

What is the endomembrane system?

A system of organelles that produce, store, and export biological molecules and degrade harmful substances.

What are peroxisomes?

Membranous sacs containing oxidases and catalases that detoxify harmful substances and neutralize free radicals.

What is the cytoskeleton?

A dynamic structure of rods running through the cytosol, consisting of microtubules, microfilaments, and intermediate filaments.

What are microtubules?

Hollow tubes made of tubulin that determine cell shape and organelle distribution.

What are microfilaments?

Strands of actin that strengthen the cell surface and are involved in endocytosis and exocytosis.

What are intermediate filaments?

Tough protein fibers that provide tensile strength and help form desmosomes.

What are centrioles?

Barrel-shaped organelles that organize the mitotic spindle during mitosis and form the bases of cilia and flagella.

What is the nucleus?

The control center of the cell that contains the genetic library and dictates protein synthesis.

What is the nuclear envelope?

A selectively permeable double membrane barrier that encloses the nucleoplasm and contains pores for molecule transport.

What are nucleoli?

Dark-staining bodies within the nucleus that are sites of ribosome production.

What is chromatin?

Threadlike strands of DNA and histones that condense into chromosomes during cell division.

What are the phases of the cell cycle?

Interphase (G1, S, G2) and the mitotic phase (mitosis and cytokinesis).

What occurs during G1 phase of interphase?

Metabolic activity and vigorous growth.

What occurs during S phase of interphase?

DNA replication.

What occurs during G2 phase of interphase?

Preparation for cell division.

Matter

The "stuff" of the universe; anything that has mass and takes up space.

States of matter

Solid - has definite shape and volume; Liquid - has definite volume, changeable shape; Gas - has changeable shape and volume.

Energy

The capacity to do work (put matter into motion).

Kinetic energy

Energy in action.

Potential energy

Energy of position; stored (inactive) energy.