Anatomy and Physiology Ch 3

Cell Membrane

A protective barrier that separates the inner contents of the cell from the external environment.

Phospholipid Bilayer

Structure of the cell membrane composed of two layers of phospholipids with hydrophilic heads facing outward and hydrophobic tails facing inward.

Hydrophilic

Water-loving; refers to the phosphate heads of phospholipids that are attracted to water.

Hydrophobic

Water-fearing; refers to the fatty acid tails of phospholipids that repel water.

Integral Proteins

Proteins embedded within the cell membrane that can facilitate transport or act as receptors.

Peripheral Proteins

Proteins that are attached to the membrane's surface, often functioning as enzymes.

Diffusion

The movement of particles from an area of higher concentration to an area of lower concentration.

Concentration Gradient

The difference in concentration of a substance across a space.

Passive Transport

Movement of substances across the cell membrane without the use of energy.

Active Transport

Movement of substances across the membrane that requires energy input, usually against a concentration gradient.

Facilitated Diffusion

The process by which substances move across the cell membrane with the assistance of carrier proteins.

Endocytosis

The process by which a cell engulfs material from the extracellular environment into a vesicle.

Exocytosis

The process by which materials are exported out of the cell by vesicular transport.

Homeostasis

The ability of a cell to maintain a stable internal environment.

Nucleus

The control center of a cell that houses genetic material (DNA).

DNA Replication

The process by which a cell duplicates its DNA before cell division.

Ribosomes

Cellular structures responsible for protein synthesis.

Cytoplasm

The jelly-like fluid that fills a cell and surrounds the organelles.

Mitosis

The process by which a cell divides its nucleus and genetic material to form two new daughter nuclei.

Cytokinesis

The division of the cytoplasm and cell body into two distinct cells after mitosis.

Chromatin

The material that makes up chromosomes, consisting of DNA and proteins.

Chromosome

A tightly coiled structure made of DNA and proteins that contains genetic information.

Stem Cells

Unspecialized cells capable of dividing without limit and differentiating into specialized cells.

Totipotent Cells

Stem cells that can differentiate into any cell type necessary for organism development.

Pluripotent Cells

Stem cells that can differentiate into nearly all cell types but cannot develop into a whole organism.

Multipotent Cells

Stem cells that have the potential to differentiate into a limited range of cell types within a particular lineage.

Transcription Factors

Proteins that regulate the expression of genes by binding to specific DNA sequences.

Cilia

Hair-like structures that help move fluids and particles across cell surfaces.

Flagella

Tail-like structures that enable cell movement, with examples including sperm cells.

Transport Proteins

Proteins that assist in the movement of substances across the cell membrane.

Glycoproteins

Proteins with carbohydrate molecules attached, involved in cell recognition.

Glycocalyx

The fuzzy coating around the cell formed from glycoproteins and carbohydrates.

Ion Channels

Integral proteins that allow specific ions to pass through the cell membrane.

Ligand

A specific molecule that binds to a receptor to trigger a biological response.

Aquaporins

Channel proteins that facilitate the rapid transport of water across cell membranes.

Osmosis

The diffusion of water through a semipermeable membrane down its concentration gradient.

Hypertonic Solution

A solution with a higher concentration of solutes compared to another, leading to cell shrinkage.

Hypotonic Solution

A solution with a lower concentration of solutes compared to another, leading to cell swelling.

Isotonic Solution

A solution with equal solute concentration on both sides of a membrane, maintaining cell shape.

Filtration

The process of moving substances through a membrane under pressure.

Sodium-Potassium Pump

An active transport mechanism that moves sodium out of and potassium into the cell.

Apoptosis

Programmed cell death that is a normal component of the development and health of multicellular organisms.

Cancer

Uncontrolled cell division resulting from failures in cell cycle regulation.

Proto-Oncogenes

Normal genes that promote cell division and growth; mutations can change them to oncogenes, leading to cancer.

Tumor Suppressor Genes

Genes that regulate cell division and prevent uncontrolled cell growth; mutations can lead to cancer.

Cell Cycle Checkpoints

Regulatory points in the cell cycle that assess the readiness of the cell for the next phase.

Cytoskeleton

A network of protein filaments and tubules that provide structure and shape to the cell.

Microfilaments

Thin protein filaments made primarily of actin, involved in cell movement and shape.

Intermediate Filaments

Filaments that provide tensile strength and maintain the shape of the cell.

Microtubules

Thick protein filaments composed of tubulin that maintain cell shape and facilitate intracellular transport.

Rough ER

The part of the endoplasmic reticulum studded with ribosomes where protein synthesis occurs.

Smooth ER

The part of the endoplasmic reticulum that synthesizes lipids and detoxifies certain chemicals.

Golgi Apparatus

The organelle responsible for modifying, sorting, and packaging proteins for secretion or delivery to other organelles.

Lysosomes

Organelles containing enzymes that digest cellular waste and macromolecules.

Mitochondria

Organelles responsible for energy production through cellular respiration.

Peroxisomes

Organelles that contain enzymes for detoxifying harmful substances and metabolizing lipids.

autophagy

The process by which a cell digests its own structures.

hepatocytes

Liver cells involved in detoxifying substances.

Chromatid

One of the two identical halves of a duplicated chromosome.

Sister Chromatids

Two identical chromatids connected by a centromere.

Centromere

The region of the chromosome where sister chromatids are joined together.

Nucleolus

A nuclear substructure that produces ribosome components.

Kinetochore

A protein structure on the centromere that links the chromatid to the mitotic spindle.

Prophase

The first stage of mitosis where chromatin condenses into chromosomes and the nuclear envelope breaks down.

Metaphase

The second stage of mitosis where chromosomes line up along the metaphase plate.

Anaphase

The third stage of mitosis where sister chromatids are pulled apart to opposite sides of the cell.

Telophase

The final stage of mitosis where two new nuclei form around the separated chromosomes.

Cyclins

Proteins that regulate the cell cycle by activating cyclin-dependent kinases.

Cyclin-Dependent Kinases (CDKs)

Enzymes that, when activated by cyclins, regulate various points in the cell cycle.

Stem Cell Research

Field of study focused on understanding stem cells and their potential to regenerate or repair tissues.

Hematopoietic Stem Cells

Stem cells found in the bone marrow that give rise to blood cells.

Induced Pluripotent Stem Cells (iPSCs)

Adult cells that have been genetically reprogrammed to an embryonic stem cell-like state.

Cell-based Therapy

Medical treatment that involves using stem cells to repair or regenerate damaged tissues.

Reactive Oxygen Species (ROS)

Highly reactive molecules that can cause cellular damage.

Oxidative Stress

Damage caused by an imbalance between the production of ROS and the body's ability to eliminate them.

Chemotherapeutic Agents

Drugs used to treat cancer by targeting rapidly dividing cells.

Epithelial Cells

Cells that form the protective outer layer of the skin and line the cavities and organs.

Connective Tissue

Tissue that supports, binds together, and protects other tissues and organs.

Muscle Tissue

Tissue responsible for the movement of the body and its parts.

Nerve Tissue

Tissue that transmits impulses and coordinates body functions.

Gene Expression

The process by which information from a gene is used to synthesize a functional gene product, typically a protein.

Base Pairing

The specific pairing of nitrogenous bases in DNA (adenine with thymine, cytosine with guanine).

Adenine

One of the four nitrogenous bases in DNA, pairs with thymine.

Thymine

One of the four nitrogenous bases in DNA, pairs with adenine.

Cytosine

One of the four nitrogenous bases in DNA, pairs with guanine.

Guanine

One of the four nitrogenous bases in DNA, pairs with cytosine.