Human Anatomy & Physiology Chapter 3 Review: Cells

Vocabulary flashcards covering cell structure, organelles, transport mechanisms, the cell cycle, mitosis, differentiation, and tumors based on Chapter 3 lecture notes.

Cell

The smallest unit of life, carrying out essential metabolic activities and specialized functions.

Composite Cell Structure

The general cellular model consisting of three main parts: the nucleus, cytoplasm, and cell membrane.

Nucleus

Organelle containing DNA that directs cell activities and is surrounded by a double nuclear envelope with pores.

Cytoplasm

The content of a cell comprised of specialized organelles and cytosol fluid.

Cell membrane

A selectively permeable, flexible boundary made of a lipid bilayer with cholesterol that regulates substance movement into and out of the cell.

Integral proteins

Transmembrane proteins that span across the lipid bilayer of the cell membrane.

Peripheral proteins

Proteins attached to only one side of the cell membrane surface.

Ribosomes

Cellular organelles responsible for protein synthesis.

Rough Endoplasmic Reticulum

Endoplasmic reticulum studded with ribosomes that functions in protein synthesis.

Smooth Endoplasmic Reticulum

Endoplasmic reticulum lacking ribosomes that functions in lipid synthesis and fat absorption.

Golgi Apparatus

Organelle that refines, packages, and secretes proteins via vesicles.

Mitochondria

Organelles with their own DNA that perform cellular respiration and ATP production.

Lysosomes

Organelles that digest materials and worn-out cell parts.

Peroxisomes

Organelles that break down fatty acids and hydrogen peroxide, and detoxify alcohol.

Cytoskeleton

Internal framework composed of microfilaments (actin), microtubules (tubulin), and intermediate fibers that provides support, enables movement, and assists in cell division.

Centrosome

Structure containing centrioles that aids in chromosome distribution during cell division.

Cilia

Short, motile cellular projections that move fluids across the surface of cells.

Flagella

Long, motile cellular projection that forms the tail of a sperm cell.

Nucleolus

Dense structure within the nucleus responsible for ribosome production.

Chromatin

Structure composed of DNA and protein within the nucleus that condenses into chromosomes during cell division.

Diffusion

Passive transport mechanism involving the net movement of particles from an area of higher concentration to lower concentration.

Facilitated diffusion

Passive transport process that uses membrane proteins to move substances down their concentration gradient.

Osmosis

Passive transport process in which water moves across a membrane toward a higher solute concentration.

Filtration

Passive transport process where molecules are forced through membranes by hydrostatic pressure.

Isotonic solution

A solution with equal osmotic pressure relative to the intracellular fluid, resulting in no net water movement.

Hypertonic solution

A solution with higher osmotic pressure relative to the cell, causing water to leave the cell and cells to shrink (crenation).

Hypotonic solution

A solution with lower osmotic pressure relative to the cell, causing water to enter the cell and cells to swell.

Active transport

Energy-requiring (ATP) movement of substances against a concentration gradient using carrier proteins or pumps, such as the $\text{Na}^+-\text{K}^+$ ATPase pump.

Endocytosis

Vesicle transport process by which large molecules enter the cell.

Pinocytosis

A form of endocytosis involving the uptake of liquids, commonly described as cell drinking.

Phagocytosis

A form of endocytosis involving the uptake of solid particles, commonly described as cell eating.

Exocytosis

Vesicle transport process where intracellular vesicles release their contents outside the cell.

Interphase

Phase of the cell cycle consisting of $G_1$ (growth), $S$ (DNA replication), and $G_2$ (growth and preparation for division).

Prophase

Initial stage of mitosis where chromatin condenses into chromosomes, the spindle apparatus forms, and the nuclear envelope breaks down.

Metaphase

Stage of mitosis during which chromosomes align at the equatorial center of the cell.

Anaphase

Stage of mitosis during which sister chromatids separate and move toward opposite poles.

Telophase

Final stage of mitosis where nuclear envelopes reform around separated chromatin and chromosomes unwind.

Cytokinesis

Division of the cytoplasm via a cleavage furrow pinching the cell into two daughter cells.

Cell Differentiation

The process by which stem cells specialize into distinct cell types through specific gene activation patterns.

Stem cells

Undifferentiated cells that retain the ability to continuously divide and specialize into various cell types.

Apoptosis

Programmed cell death that occurs as a normal part of development.

Benign tumors

Local, slow-growing, non-cancerous cellular growths.

Malignant tumors

Rapidly growing cancerous growths that invade surrounding tissues and can metastasize through the bloodstream or lymphatic system.