Exam 1 Practice Questions

What is the main function of epithelial tissue?

Lining and covering body surfaces; also forms glands.

What is the main function of connective tissue?

Supports, connects, protects, and binds body structures; includes blood.

What is the main function of muscle tissue?

Contraction to produce movement.

What is the main function of neural tissue?

Fast communication and information processing.

Which tissues contain excitable cells?

Neural tissue and muscle tissue.

What is an endocrine gland?

An epithelial gland that secretes hormones into the blood.

What is an exocrine gland?

An epithelial gland that secretes through a duct.

What is intracellular fluid (ICF)?

Fluid inside cells.

What is extracellular fluid (ECF)?

Fluid outside cells; includes plasma and interstitial fluid.

What is interstitial fluid (ISF)?

Fluid between tissue cells; the largest ECF compartment.

What is plasma?

The fluid portion of blood; part of the ECF.

Where is most body water found?

In the ICF.

Which substances are higher in ICF?

K⁺, Mg²⁺, ATP, amino acids, proteins, and Pi.

Which substances are higher in ECF?

Na⁺, Ca²⁺, Cl⁻, and HCO₃⁻.

Define homeostasis.

Maintenance of a regulated variable at a relatively constant level in the internal environment.

What is a regulated variable?

A condition the body monitors and controls.

What is a set point?

The target value for a regulated variable.

What is a set range?

The acceptable range around a target value.

What do receptors/sensors do?

Monitor the regulated variable and send information to the integrating center.

What does the integrating center do?

Compares incoming information to the set point/set range.

What is an error signal?

A signal produced when the regulated variable differs from the set point/set range.

What do effectors do?

Produce a response that changes the regulated variable.

What is the basic homeostatic pathway?

Receptor → integrating center → effector → response.

What is negative feedback?

A response that counteracts the original change.

Give an example of negative feedback.

High ATP inhibits a key glycolysis enzyme, slowing glycolysis.

What is positive feedback?

A response that amplifies the original change.

Give an example of positive feedback.

Blood clotting or childbirth.

In the childbirth feedback loop, what is the integrating center?

Posterior pituitary.

In the childbirth feedback loop, what is the effector organ?

Uterine smooth muscle.

What is the central dogma?

DNA → RNA → protein.

What is transcription?

Copying DNA information into RNA.

What is translation?

Using mRNA to build a protein.

Where does transcription occur?

In the nucleus.

Where does translation occur?

At ribosomes in the cytoplasm or rough ER.

What are the four major classes of biomolecules?

Carbohydrates, lipids, proteins, and nucleic acids.

What are carbohydrates made of?

Sugars joined by glycosidic bonds.

Give examples of carbohydrates.

Glycogen, starch, and glucosamine.

What are proteins made of?

Amino acids joined by peptide bonds.

Give examples/functions of proteins.

Transporters, receptors, hormones, and structural proteins.

What are nucleic acids made of?

Nucleotides.

What are nucleotides made of?

5-carbon sugar + phosphate group + nitrogenous base.

Give examples of nucleic acids.

DNA, RNA, and ATP.

What are lipids mostly like chemically?

Mostly hydrophobic.

What lipid examples are in the quiz?

Eicosanoids, steroids, and T3/T4.

What is a protein's primary structure?

Linear sequence of amino acids.

What is secondary protein structure?

Alpha helices and beta sheets.

What is tertiary protein structure?

Overall 3D folding of one polypeptide.

What is quaternary protein structure?

Two or more polypeptide subunits together.

What is metabolism?

The sum of chemical reactions occurring in a cell.

What is a catabolic reaction?

Breaks larger molecules into smaller molecules.

What is an anabolic reaction?

Builds larger molecules from smaller molecules.

What is oxidation?

Loss of electrons.

What is reduction?

Gain of electrons.

What does OIL RIG mean?

Oxidation Is Loss; Reduction Is Gain.

What is phosphorylation?

Adding a phosphate group.

What is dephosphorylation?

Removing a phosphate group.

What is a metabolic pathway?

A sequence of reactions where one product becomes the next reactant.

What does negative ΔG indicate?

A thermodynamically favorable reaction.

What is the main function of mitochondria?

Aerobic respiration and apoptosis.

What do ribosomes do?

Synthesize proteins.

What is the function of the nucleus?

Stores DNA; site of transcription and RNA processing.

What does smooth ER do?

Ca²⁺ storage, detoxification, and steroid synthesis.

What does rough ER do?

Synthesizes proteins for membranes or secretion.

What does the cytoskeleton do?

Helps maintain cell shape and moves chromosomes.

What do peroxisomes do?

Break down fatty acids, amino acids, and toxins.

What do lysosomes do?

Break down cellular debris and recycle materials.

What does the Golgi apparatus do?

Modifies, sorts, and packages proteins.

What are the major components of a cell membrane?

Phospholipids, membrane proteins, cholesterol, and carbohydrates.

What does amphipathic mean?

Having both hydrophilic and hydrophobic regions.

How are phospholipids arranged?

Hydrophilic heads face water; hydrophobic tails face inward.

What does cholesterol do in the membrane?

Helps regulate membrane fluidity.

What do membrane proteins do?

Transport, signaling, recognition, enzymatic, and anchoring functions.

What do membrane carbohydrates do?

Cell recognition and communication.

What is a tight junction?

A junction that seals neighboring cells together.

What proteins form tight junctions?

Occludins and claudins.

What is a desmosome?

A strong junction that holds cells together during mechanical stress.

What is a gap junction?

A direct communication channel between neighboring cells.

What proteins form gap junctions?

Connexins.

What can pass through gap junctions?

Small ions and molecules.

What is a channel protein?

A membrane protein that forms a passageway.

What is a carrier protein?

A protein that binds a substance and changes shape to move it.

What is simple diffusion?

Movement down a concentration gradient without a transport protein.

What is facilitated diffusion?

Movement down a gradient through a channel or carrier.

What is active transport?

Movement against a gradient using energy.

What is primary active transport?

Uses ATP directly.

What is secondary active transport?

Uses energy stored in another substance's gradient.

What is bulk transport?

Vesicle-based movement into or out of a cell.

What is endocytosis?

Bringing substances into a cell using vesicles.

What is exocytosis?

Releasing substances when vesicles fuse with the membrane.

What is phagocytosis?

Uptake of large particles; "cell eating."

What is pinocytosis?

Uptake of extracellular fluid; "cell drinking."

What is receptor-mediated endocytosis?

Selective uptake after a substance binds a receptor.

What is transcytosis?

Vesicle movement across a cell from one side to the other.

What is transcellular movement?

Movement through epithelial cells.

What is paracellular movement?

Movement between epithelial cells.

What is osmosis?

Net movement of water toward higher effective solute concentration.

What is tonicity?

A solution's effect on cell volume.

What happens to a cell in a hypertonic solution?

Water leaves; cell shrinks.

What happens to a cell in a hypotonic solution?

Water enters; cell swells.

What happens to a cell in an isotonic solution?

No net water movement; volume stays about the same.