Studied by 13 peopleCell Theory (three statements)
1. All living things are composed of one or more cells
2. Cells are the basic structural and functional units of life
3. All cells arise from the division of other cells
Cell Membrane
A thin flexible film that separates the contents of the cell from the extracellular fluid and controls the movement of fluids in and out of the cell.
Chromatin (DNA)
Genetic material found in cells that stores all the instructions needed for a cell's activities.
What is Cytosol?
The aqueous solution inside the cell where all the cell's organelles are suspended.
Nucleus
The control center of the cell, responsible for regulating cell activities.
Cytoplasm
The cytosol and all the cell organelles outside the nucleus but within the cell membrane.
Cell Wall
An additional outer covering found in plant cells that provides rigidity while allowing water and dissolved materials to pass through easily.
Unicellular Organisms
Organisms consisting of only one cell that must perform all functions of life for that cell.
Seven Functions of Life
1. Nutrition 2. Metabolism 3. Growth 4. Response 5. Excretion 6. Homeostasis 7. Reproduction
Surface Area to Volume Ratio
The ratio of surface area to volume in a cell, which affects the rate of chemical reactions, absorption of substances, and removal of waste products.
Multicellular Organisms
Organisms consisting of a single mass of cells that are fused together, accompanied by cellular specialization and division of labor.
Emergent Properties
The characteristics of a whole organism that arise from the interactions and cooperation of its cells.
Division of Labour
The concept that different cells in a multicellular organism perform different functions to allow the organism to carry out complex tasks.
Tissue
A group of cells that specialize in the same way to perform a specific function more efficiently than individual cells.
Differentiation
The process by which cells develop in different ways to carry out specific functions.
Cell Differentiation
When different sequences of genes are expressed in different cell types.
Gene expression
The process by which genes are activated and their instructions are used to create specific proteins or molecules.
Stem cell
An unspecialized cell that can divide and renew itself for long periods and has the potential to differentiate into specialized cell types.
Plasticity (transdifferentiation)
The ability of stem cells from one tissue to generate the differentiated cell types of another tissue.
Pluripotent
The ability of a single stem cell to give rise to all the various cell types in the body.
Adult stem cells
Undifferentiated cells found in differentiated tissues that can renew themselves and differentiate into specialized cell types.
Embryonic stem cells
Primitive cells derived from a 5-day preimplantation embryo that have the potential to become a wide variety of specialized cell types.
Umbilical cord blood stem cells
Stem cells obtained from the blood remaining in the placenta and umbilical cord after a baby is delivered.
Stromal Stem Cells
Stem cells derived from menstrual blood that exhibit stem cell properties such as self-renewal and multipotency.
Why embryos?
Stem cells derived from embryos that have the capacity to differentiate into all types of cells/tissues and are easier to grow in culture.
Therapeutic stem cells
Stem cells used for medical purposes, such as regenerating skin for burn victims or replacing damaged cells in Parkinson's patients.
Cell rejection
Concern that transplanted stem cells may be rejected by the recipient's immune system.
Insulation tissue
Tissue that surrounds and protects neurons.
Microenvironment
The immediate surroundings of a cell, including neighboring cells and molecules.
Nucleus
The control center of the cell that contains DNA and directs all cell activities.
Nuclear envelope
A double membrane that separates the nucleus from the cytoplasm and controls the passage of molecules.
Nucleoplasm
The fluid inside the nucleus that contains nucleic acids used in making RNA and DNA.
Nucleolus
A denser region inside the nucleus involved in ribosomal production.
Ribosomes
Organelles that produce proteins through protein synthesis.
Endoplasmic Reticulum (ER)
A system of channels attached to the nuclear envelope that manufactures proteins (rough ER) or synthesizes lipids (smooth ER).
Vesicles
Membrane-bound structures that transport molecules within the cell.
Golgi Apparatus
A stack of curved membrane sacs that chemically modifies fats and proteins produced in the ER and packages them in vesicles.
Lysosomes
Membrane-enclosed sacs containing enzymes that break down old or unnecessary parts of the cell and destroy microorganisms.
Peroxisomes
Membrane-enclosed sacs containing enzymes that catalyze redox reactions and break down fatty acids and alcohol molecules.
Vesicles ("Vacuoles")
Large membrane-bound sacs filled with a watery solution, responsible for storing sugars, minerals, and proteins.
Mitochondria
Membranous organelles responsible for cellular respiration and producing energy for the cell.
Plastids
Membranous organelles found only in plant cells, with the chloroplast being the most important, containing chemicals for photosynthesis.
Microtubules and Centrioles
Small cylindrical fibers responsible for moving chromosomes during cell division, with centrioles serving as an anchor point.
Cilia & Flagella
Whip-like structures made of microtubules, used for locomotion and creating currents in fluid.
Prokaryotic Cells
Cells without a defined nucleus, small in size, and found almost everywhere, with a cell wall made of peptidoglycan.
Nucleoid
A circular molecule containing DNA in prokaryotic cells.
Binary fission
A form of asexual reproduction in prokaryotic cells where the single circular DNA molecule is copied and each moves to opposite ends of the cell, followed by division of cytoplasm and cell.
Eukaryotic cells
Cells with compartmentalized structure, including a nucleus containing the cell's chromosomes and other organelles with distinctive structure and function.
Compartmentalization
The division of a cell into different compartments or organelles, allowing for concentration of enzymes and substrates, containment of harmful substances, different pH levels, and movement of organelles and their contents.
Cell membrane
A phospholipid bilayer that surrounds the cell and controls the movement of molecules in and out.
Amphipathic
Substances that have both hydrophilic and hydrophobic properties, such as phospholipids.
Phospholipid bilayer
The double layer of phospholipids in the cell membrane, with hydrophilic heads facing the water and hydrophobic tails facing each other.
Membrane proteins
Proteins embedded in the cell membrane that carry out various tasks, including hormone binding, enzyme activity, cell adhesion, cell-to-cell communication, and transport of molecules across the membrane.
Integral proteins
Membrane proteins that extend across the membrane, with hydrophobic parts embedded in the hydrocarbon chains of the cell membrane and hydrophilic ends projecting through the phosphate parts of the membrane.
Channel proteins
Integral proteins that transport water and ions across the cell membrane.
Carrier proteins
Integral proteins that transport small molecules across the cell membrane, such as glucose.
Surface proteins
Integral proteins used for binding and can attach movement structures like cilia and flagella, as well as serve as receptor sites for hormones.
Pumps
Carrier proteins that move molecules against the concentration gradient (requires energy - ATP)
Peripheral Proteins
Hydrophilic proteins on the surface of the membrane, not embedded in the membrane
Carbohydrate Chains
Carbohydrate chains attached to membrane proteins, involved in cell adhesion
Cholesterol
Present in animal cell membranes, helps control fluidity of cell membranes
Passive Transport
Processes that allow substances to move in and out of the cell without requiring energy (ATP)
Simple Diffusion
Movement of particles from an area of high concentration to an area of lower concentration until equilibrium is reached
Concentration Gradient
Difference in concentration between two areas
Dynamic Equilibrium
State of balance where particles move at equal rates in all directions
How does temperature affect the rate of diffusion?
Affects the rate of diffusion, higher temperatures result in faster diffusion
How does concentration affect the rate of diffusion?
More solute molecules in the solution lead to faster dynamic equilibrium
How does Molecule Size affect the rate of diffusion?
Larger molecules have more difficulty diffusing across the membrane
How does Molecule Polarity affect the rate of diffusion?
Small polar molecules have lower diffusion rates compared to non-polar molecules of the same size
Molecule or Ion Charge
Charged molecules and ions cannot diffuse across a cell membrane
Facilitated Diffusion
Diffusion of solutes across a membrane along its concentration gradient, assisted by transmembrane proteins
Channel Proteins
Transmembrane proteins that form a tunnel for ions or small polar molecules to pass through the cell membrane.
Carrier Proteins
Transmembrane proteins that bind to molecules, change shape, and transport them across the cell membrane.
Osmosis
The net movement of water across a selectively permeable membrane from an area of high concentration to an area of low concentration.
Aquaporins
Water channels in some cells that greatly increase the membrane's permeability to water.
Isotonic Solutions
Solutions that have equal solute concentrations.
Hypertonic solution
A solution with a higher concentration of solutes than another.
Hypotonic solution
A solution with a lower concentration of solutes than another.
Hemolysis
The swelling and bursting of red blood cells due to water diffusing into the cells in a hypotonic solution.
Crenation
The loss of water and shrinking of red blood cells in a hypertonic solution.
ATP (Adenosine Triphosphate)
A molecule that stores and releases energy for cellular processes.
Active Transport
The movement of substances through a membrane against a concentration gradient using trans-membrane carrier proteins and energy from ATP.
Sodium-potassium pump
An important type of active transport pump found in cell membranes, required for proper function of nerve and muscle cells.
Membrane-Assisted Transport
Movement of molecules that are too large to cross the cell membrane using vesicles.
Endocytosis
The process in which the cell membrane engulfs large amounts of material into the cell.
Phagocytosis
The transport of solids into the cell through the formation of a phagocytic vesicle.
Pinocytosis
The engulfing of extracellular fluid by the cell membrane to form a pinocytic vesicle.
Exocytosis
Cells moving large amounts of material out of the cell, essentially the reverse of endocytosis.
Secretory vesicle
A vesicle containing material destined to leave the cell, which fuses with the cell membrane during exocytosis.
Simple diffusion
The movement of substances from an area of higher concentration to an area of lower concentration, without the need for energy.
Facilitated diffusion
The movement of substances from an area of higher concentration to an area of lower concentration, facilitated by channel or carrier proteins.
Active transport
The movement of substances from an area of lower concentration to an area of higher concentration, requiring energy and carrier proteins.
Endocytosis
Cells moving material into the interior of the cell by forming vesicles from the cell membrane.
Biogenesis
The concept that all living things come from other living things.
Abiotic synthesis
The synthesis of small organic molecules from non-living components.
Polymers
Large molecules formed by the joining of smaller molecules (monomers).
Protobionts
Early "cells" that exhibit some properties of life, formed spontaneously from organic compounds.
RNA
The first genetic material discovered, capable of self-replication and acting as catalysts in cells.
DNA
More stable than RNA, possibly formed from RNA and serves as the template for protein synthesis.
Endosymbiosis
One species living permanently inside another, benefiting both organisms.
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