C) LECTURE CH3 CARDS

A complete set of 80 vocabulary flashcards covering cell structure, transport mechanisms, organelles, gene expression, and cell division based on the lecture transcripts.

Prokaryotic Cell

A relatively simple cell that does not have a membrane bound nucleus or membrane bound organelles. Example: Bacteria are prokaryotic cells.

Eukaryotic Cell

A complex cell containing a membrane bound nucleus and specialized organelles. Example: Human cells are eukaryotic cells.

Plasma Membrane

The flexible selectively permeable outer boundary of the cell. It separates the intracellular environment from the extracellular environment and controls what enters and leaves.

Cytoplasm

All cellular material between the plasma membrane and nucleus. It includes cytosol and organelles. Example: Mitochondria and ribosomes are located in the cytoplasm.

Cytosol

The fluid portion of the cytoplasm surrounding the organelles where many chemical reactions occur. Example: Many cellular reactions take place in the cytosol.

Organelle

A specialized structure inside a cell that performs a particular function. Example: A mitochondrion is an organelle that produces ATP.

Nucleus

A large organelle that contains the cell's genetic material and helps control cell activities.

Fluid Mosaic Model

A model describing the plasma membrane as a flexible phospholipid bilayer containing proteins and other molecules that can move within it.

Phospholipid Bilayer

The double layer of phospholipids that forms the basic structure of the plasma membrane. Cholesterol and glycolipids are also present.

Integral Proteins

Proteins embedded within the lipid bilayer.

Transmembrane Proteins

Integral proteins that extend completely through the phospholipid bilayer. Example: A transmembrane channel can allow ions to cross the membrane.

Peripheral Proteins

Proteins attached to the inner or outer surface of the membrane rather than passing completely through it.

Ligand

A specific signaling molecule that binds to a matching receptor. Example: A hormone can act as a ligand.

Cell Adhesion Molecules or CAMs

Membrane proteins that help neighboring cells attach to one another. Example: CAMs help cells stay organized within tissues.

Selective Permeability

The ability of the plasma membrane to allow some substances to cross while restricting others.

Passive Transport

Movement across a membrane down a concentration gradient without directly using ATP.

Active Transport

Transport that requires cellular energy and can move substances against their concentration gradient. Example: The sodium potassium pump uses ATP.

Concentration Gradient

A difference in the concentration of a substance between two areas. Example: If oxygen is higher outside a cell than inside an oxygen concentration gradient exists.

Simple Diffusion

Passive movement of small or lipid soluble molecules directly through the membrane from high concentration to low concentration. Example:

Channel Mediated Facilitated Diffusion

Passive movement down a concentration gradient through a membrane channel protein.

Carrier Mediated Facilitated Diffusion

Passive transport in which a substance binds to a carrier protein that changes shape and moves it across the membrane.

Osmosis

The passive movement of water across a selectively permeable membrane. Water moves toward the side with the greater concentration of nonpenetrating solute. Example: If more nonpenetrating solute is outside a cell water moves out.

Aquaporins

Membrane proteins that form specialized channels for water.

Isotonic Solution

A solution with approximately equal effective solute concentration compared with the cell. There is no net movement of water and cell size stays about the same.

Hypertonic Solution

A solution with a higher concentration of nonpenetrating solute than the cell. Water moves out and the cell shrinks. Example: A red blood cell shrinks in a hypertonic solution.

Hypotonic Solution

A solution with a lower concentration of nonpenetrating solute than the cell. Water moves into the cell and the cell swells. Example: A red blood cell swells in a hypotonic solution.

Crenation

Shrinking and shriveling of a red blood cell after it loses water in a hypertonic solution. Example: A red blood cell placed in concentrated salt solution crenates.

Hemolysis

Bursting of a red blood cell caused by excessive water entering it.

Hypertonic Solution With a Nonpenetrating Solute

The nonpenetrating solute cannot enter the cell. Water therefore moves out toward the higher concentration of nonpenetrating solute and the cell shrinks.

Sodium Potassium Pump

An active transport pump that uses one ATP to move 3 sodium ions out of the cell and 2 potassium ions into the cell. Example: It helps maintain sodium and potassium concentration gradients.

Secondary Active Transport

Transport that uses energy stored in an ion gradient to move another substance against its concentration gradient.

Antiporter

A transport protein that moves two substances in opposite directions across the membrane. Example: One substance enters while another leaves the cell.

Symporter

A transport protein that moves two substances in the same direction across the membrane.

Endocytosis

Active vesicular transport that brings substances into the cell inside membrane vesicles.

Example: the cell literally opens a mouth and eats a particle because its too big to pass through the membrane.

Exocytosis

A process in which vesicles fuse with the plasma membrane and release their contents outside the cell.

Receptor Mediated Endocytosis

Selective endocytosis in which a ligand first binds to a specific membrane receptor before a vesicle forms.

Phagocytosis

Cell eating. A cell surrounds and brings in large particles such as bacteria or cellular debris.

Pinocytosis

Cell drinking. A cell takes in extracellular fluid and dissolved substances. Example: A cell takes in droplets of surrounding fluid.

Cytoskeleton

A network of protein fibers that provides cell shape and support and helps move cellular components. Its major parts are microfilaments intermediate filaments and microtubules.

Microfilaments

The thinnest cytoskeletal fibers. They are made mainly of actin and help with cell shape and movement. Example: Actin microfilaments help cells change shape.

Intermediate Filaments

Strong cytoskeletal fibers that help maintain cell shape and stabilize cellular structures.

Microtubules

Large hollow tubes made of tubulin that help with cell structure organelle movement cilia and cell division.

Microfilaments vs Intermediate Filaments vs Microtubules

Microfilaments are thin actin fibers involved in shape and movement. Intermediate filaments provide strength and stability. Microtubules are large hollow tubes involved in transport cilia and chromosome movement.

Centrosome

The main microtubule organizing center near the nucleus. It contains two centrioles.

Centrioles

Two cylindrical structures inside the centrosome made from microtubule triplets.

Pericentriolar Material

Material surrounding the centrioles ,organizes microtubules.

Cilia

Short hairlike projections made from microtubules that move substances along the cell surface.

Flagellum

A long whip like projection that moves an entire cell. Example: A sperm cell uses its flagellum for movement.

Ribosomes

Nonmembranous structures that make proteins.

Rough Endoplasmic Reticulum

A membrane network covered with ribosomes that helps make and process proteins.

Smooth Endoplasmic Reticulum

A membrane network has no ribosomes. makes lipids, helps detoxify chemicals , and can store calcium.

Golgi Complex

An organelle that modifies sorts packages and transports proteins and other materials.

Cisternae

Flattened curved membrane sacs that make up the Golgi complex.

Lysosomes

Vesicles containing digestive enzymes that break down waste and unwanted materials. Example: A lysosome can digest damaged cellular components.

Peroxisomes

Small organelles that help break down fatty acids and detoxify harmful substances. Example: Liver cells contain many peroxisomes.

Proteasomes

Protein complexes that destroy damaged faulty or unneeded proteins.

Mitochondria

Organelles that produce most of the cell's ATP through cellular respiration.

Cristae

Folds of the inner mitochondrial membrane that increase surface area for ATP producing reactions.

Mitochondrial Matrix

The fluid filled space inside the inner mitochondrial membrane containing enzymes ribosomes and mitochondrial DNA.

Nuclear Envelope

A double membrane containing nuclear pores that separates the nucleus from the cytoplasm.

Nucleolus

A structure inside the nucleus that produces ribosomal subunits.

Chromatin

Uncoiled DNA and associated proteins found in the nucleus during interphase.

Chromosome

Highly condensed DNA \, packaged with proteins and especially visible during cell division. .

Histones

Proteins that DNA wraps around to help package and organize genetic material.

Nucleosome

A section of DNA wrapped around a core of histone proteins.

Gene

A segment of DNA containing instructions for making a functional product often a protein.

Central Dogma

The general flow of genetic information from DNA to RNA to protein.

Transcription

The process of copying information from DNA into RNA

Translation

The process in which ribosomes read mRNA instructions and assemble amino acids into a protein

Promoter

A DNA sequence where RNA polymerase binds to begin transcription.

RNA Polymerase

The enzyme that makes an RNA copy from a DNA template.

Introns

Noncoding regions removed from pre mRNA before mature mRNA is produced.

Exons

Regions of pre mRNA that remain and are joined together to form mature mRNA.

Codon

A three nucleotide sequence on mRNA that specifies an amino acid or stop signal. Example: Ribosomes read mRNA three nucleotides at a time.

Anticodon

A three nucleotide sequence on tRNA that pairs with a complementary mRNA codon. Example: A tRNA anticodon matches the appropriate codon during translation.

Somatic Cell Division

Division of body cells by mitosis and cytokinesis that produces two genetically identical diploid daughter cells.

Homologous Chromosomes

Matching chromosome pairs that carry genes for the same types of traits.

Diploid Cell

A cell containing two complete sets of chromosomes. Human somatic cells normally contain 46 chromosomes arranged in 23 pairs.

Interphase

The portion of the cell cycle containing G1 S and G2. The cell grows performs normal functions copies DNA and prepares for division.

Cell Cycle

The sequence of events a cell goes through as it grows and divides. G1 is growth and normal function. S is DNA replication. G2 prepares for division. Mitosis divides the nucleus. Cytokinesis divides the cytoplasm.

Mitosis

Division of the nucleus that separates duplicated chromosomes into two identical sets. Its major stages are prophase metaphase anaphase and telophase.

Prophase

Chromosomes condense and become visible. The nuclear envelope begins breaking down and the mitotic spindle forms.

Metaphase

Duplicated chromosomes line up across the middle or equator of the cell.

Anaphase

Sister chromatids separate and move toward opposite ends of the cell. Example: Chromosomes being pulled toward opposite poles indicate anaphase.

Telophase

Chromosomes reach opposite poles begin to uncoil and new nuclear envelopes form around each set. Example: Two newly forming nuclei indicate telophase.

Cytokinesis

Division of the cytoplasm that produces two separate daughter cells. Example: Cytokinesis completes the physical separation of two daughter cells.

Cleavage Furrow

An indentation of the plasma membrane that forms around the equator of an animal cell during cytokinesis.

Meiosis

Reproductive cell division that produces haploid gametes with half the normal chromosome number.

Passive vs Active Transport Application

Passive transport moves substances down a concentration gradient without directly using ATP. Active transport uses cellular energy and can move substances against a concentration gradient.

Diffusion Direction Application

A substance undergoing diffusion moves from higher concentration to lower concentration if it can cross the membrane. Example: If oxygen concentration is high outside a cell and low inside oxygen moves into the cell.

Osmosis Direction Application

Water moves across a selectively permeable membrane toward the side containing the greater concentration of nonpenetrating solute.

Tonicity Application

Isotonic means the cell stays about the same size. Hypotonic means water enters and the cell swells. Hypertonic means water leaves and the cell shrinks.

Transport Protein Types

Channels form openings through the membrane. Carriers bind substances and change shape. Pumps use energy to move substances against gradients.

Phagocytosis vs Pinocytosis

Phagocytosis is cell eating and brings in large particles. Pinocytosis is cell drinking and brings in extracellular fluid and dissolved substances. Both are forms of endocytosis. .