Ch:1 Cell Structure and Function Flashcards
Metabolism
Sum of reactions that take place to build up and break down the body.
Homeostasis
The body’s ability to maintain a stable and constant internal condition.
Protein
Large and complex molecule consisting of amino acids (which contain nitrogen) that are essential for living cells.
Pathogen
Disease-causing agent; usually bacteria, virus, or fungi.
Enzyme
Substance that helps catalyze chemical reactions.
Epithelial Tissue
Tissue composed of cellular layers that protect outer surfaces of the human body such as skin, mucosa, and intestinal lining.
Connective Tissue
Supportive tissue, such as ligaments, tendons, and fascia, formed from a fibrous matrix.
Muscle Tissue
Tissue consisting of bundles of cells that contract when stimulated.
Nervous Tissue
Tissue capable of conducting impulses that help to connect and communicate signals to other parts of the body.
Organelle
Component of the cell that is responsible for a specific task.
Cytoplasm
Fluid medium inside of the cell, but outside of the nucleus, that surrounds organelles.
Plasma Membrane
Lipid bilayer that is permeable to certain compounds that contains the cell.
LIpid
Organic substance that is insoluble in water; provides structure, storage, and messenger functions in the body.
Cholesterol
Lipid/sterol contained in the body’s cells and fluids that acts as a precursor to hormones and bodily structures.
Phospholipids
A type of lipid with a hydrophilic phosphate group “head” and hydrophobic fatty acid “tail” that forms cell membranes.
Hydrophilic
Strong affinity for water.
Hydrophobic
Lack of affinity for water.
Cytosol
Internal fluid portion of the cell.
Mitochondria
Organelles that supply the cells’ energy/ATP.
Oxidize
To combine with oxygen.
Adenosine Triphosphate (ATP)
Adenosine molecule with three phosphate groups that supplies energy for the cell.
Cristae
Internal compartments of the mitochondria.
Mitochondrial Density
Quantity of mitochondria per unit volume.
Mitochondrial Quality
Specific attributes of mitochondria.
Reactive Oxygen Species (ROS)
Various substances formed as a byproduct of metabolism that are highly reactive due to the unpaired electron shell.
Free Radicals
Reactive atom with one or more electrons.
Chromosomes
Organized structure of DNA, found within cells, that contains the genes of an organism.
Transcription
Construction of mRNA from a DNA molecule.
Translation
Forming a protein molecule based on the information contained in the mRNA.
Endoplasmic Reticulum
Cytoplasmic membrane that translates proteins.
Golgi Apparatus
Cytoplasmic organelle necessary for the modification and transport of proteins.
Ribosomes
A complex rich in RNA and protein found in cells.
Glycoproteins
Protein that contains a carbohydrate group, involved in membrane integrity.
Ribonucleic Acids (RNA)
Various nucleic acids on a single strand containing ribose and uracil, necessary for the control of cell activities.
Cisternae
Flattened membrane disc of Golgi Apparatus.
Vesicles
Fluid filled pouch/sac that can transport and store compounds.
Lysosome
Organelle containing hydrolytic enzymes.
Microorganism
Organism of microscopic size.
Peroxisome
Cytoplasmic organelle with enzymes that help with the breakdown of fatty acids and other macromolecules.
Detoxify
To remove a poison or toxin from the body.
Receptor-Ligand Binding Complex
A complex formed between a receptor and a substance to allow for further cellular activity.
Signal Transcription
Conversion of one signal to another by a cell.
Second Messenger
Substance that mediates intracellular activity by relaying a signal from an extracellular molecule.
Ligand
Any substance that binds specifically and reversibly to another chemical entity to form a larger complex.
Transport Protein
Protein that moves compounds across a membrane.
Facilitated Diffusion
Transport that requires a carrier molecule; occurs when diffusion of a substance on its own is not possible.
Active Transport
Movement of particles from an area of low concentration to an area of high concentration.
Substrate
Substance acted upon by an enzyme.
Lock-and-Key Model
Model that explains enzyme specificity.
Induced Fit Model
Model that suggests enzymes are rather flexible structures.
Co-Enzyme
Non-protein compound that forms the active portion of an enzyme system.
Catalyze
Initiate or increase the rate of a chemical reaction.
