The Cellular Level of Organization Flashcards
Cell
Basic living, structural, functional unit of the body
Cell biology (cytology)
Study of cells
Plasma membrane
Forms sell flexible outer surface and separate the internal and external environment
Cytoplasm
Consists of all the cellular contents between the plasma membrane and the nucleus
has two compartments cytosol and organelles
Organelles
Characteristic shape and function in cell
Nucleus
Largest organelle that houses most cell DNA
Control centre of the cell
Chromosome
Single molecule of DNA
Genes
Hereditary units
Fluid Mosaic model
Continually moving sea of fluid lipids that contain many different protein
Plasma membrane functions
Barrier separating inside and outside cell
Control flow of substances inside and out of the cell
Helps identify the cell to other cells
Participates in intercellular signalling
Lipid bilayer
Basic structural framework of plasma membrane
Three lipid molecules that make back-to-back layers
Phospholipids glycolipids and cholesteryl
Amphipathic
Polar and nonpolar lipids
Phospholipids are polar head hydrophilic
Fatty acid tails or nonpolar hydrophobic
Integral proteins
Extend into and through the lipid bilayer firmly embedded
Transmembrane proteins
Span entire lipid bilayer
Peripheral proteins
Not firmly embedded attached to polar heads or integral proteins ends
Ion channel
Pore through which ion can flow
Carrier protein
Transport specific substance across a membrane
Receptor protein
Recognizes ligand and alter cell function
Enzyme protein
Catalyzes reaction inside or outside cell
Linker protein
Anchors filaments inside and outside plasma membrane
Cell identity marker
Distinguishes your cells from anyone else glycoprotein
Membrane fluidity
Easily rotating move sideways
Allows interaction with the plasma membrane
Allows movement of membrane components responsible for cell processes
(cell movement, growth, division, secretion and formation of cellular junctions)
Allows lipid bilayer to self seal it punctured
Membrane permeability
Structure permits passage of substances
Selective permeability
Permit Some substances more than others
Concentration gradient
Difference in the concentration of a chemical from one place to another
Inner surface plasma membrane
More negatively charged
Outer surface plasma membrane
Or positively charged
Electrical gradient
Difference in electrical charge between two regions
Types of transport
Passive and active
Types of passive transport
Simple diffusion
facilitated diffusion
osmosis
Types of active transport
Active transport (primary secondary) transport in vesicles (endocytosis and exocytosis)
Passive transport
Substances move down its concentration or electrical gradient across the membrane using only it’s own Kinetic energy
Active transport
Cellular energy is used to drive a substance uphill against its gradients
Diffusion
Passive, random mixing of particles in a solution
Moves from a high to low concentration
Five factors of diffusion rate
Steepness of concentration gradient temperature
mass of diffusing substance
surface area
diffusion distance
Simple diffusion
Substances move freely through lipid bilayer without help of transport protein
Facilitated diffusion
Integral membrane protein assist specific substances across (channel or carrier)
Osmosis
Movement of solvent (water) through selective permeable membrane
area of high to low water concentration
Tonicity
Measure of a solution’s ability to change cell volume by altering water content
Isotonic solution
Same concentration both sides
Hypotonic solution
Solution has a lower concentration of solute then inside cell
Hypertonic solution
Solution has a higher concentration of solutes then inside cell
Crenation
Shrinkage of cell
Active transport
Energy is required for carrier proteins to move solutes across the membrane against a concentration gradient
3 types of active transport
Primary (ATP from hydrolysis)
secondary (Energy stored in concentration gradient)
transport in vesicles
Two types of Active transport by vesicle
Endocytosis
exocytosis
Endocytosis
Into the cell
Exocytosis
Out of the cell
Phagocytosis
Cell eating endocytosis that engulfs large particles
Cytoplasm
Consists of all cellular material between plasma membrane and nucleus
two compartments cytosol and organelles
Three types of filaments of cytoskeleton
Microfilaments
intermediate filaments
microtubules
Cytoskeleton
Protein filaments that extend through cytosol
Organelle
Specialize structure & shape that perform specific functions, growth maintenance and reproduction in cell
Cilia and flagella
Short, hairlike and extend from the cell suface to move fluid
Like Cilia but longer can move an entire cell
Nucleus
Contains cells genetic information, organized into chromosomes
control centre of the cell
Mitochondria
Considered to be the powerhouse of the cell respiration occurs here in ATP is generated
Endoplasmic reticulum
Rough ER – ribosomes on outside process of protein produced by ribosomes
Smooth ER – synthesizes lipids, phospholipids and steroids
Assembly line
Golgi apparatus
Re-Processes and packs proteins and lipids produced by the cell
Post office
Lysosome
Controls Digestive enzymes to engulf aged organelles, food and bacteria
Peroxisome
Contains enzymes that get rid of peroxide from the cell
Ribosomes
Protein synthesis
Centrosome
Microtubule organizing centre
two components centrioles and pericentriolar matrix (Forms mitotic spindle during cell division and build microtubules in non-dividing cells
Proteasone
Barrel shaped, degrades damaged or faulty proteins by cutting into smaller peptides
Wood chipper
Apoptosis
Genetically programmed death of cell
Chromatin
Complex of DNA and some RNA and proteins
Genome
Genetic information
Genomics
Study of relationship between genome and biological function of an organism
Chromosome
Highly coiled and folded DNA molecule combined with protein molecules
Transcription
Information encoded in a specific region of DNA to produce a specific molecule of RNA (copied)
Translation
RNA attaches to a ribosome, then translated into sequence of amino acids to form new protein molecule
Two types of protein synthesis
Transcription
translation
Gene expression
Genes DNA issued as a template for synthesis of a specific protein
Cell division
Process by which cells reproduce themselves
Somatic cell
any body cell other than germ cell
Germ cell
Gamete, cell designed to become gamete
Mitosis
Cell undergoes a nuclear division
Cytokinesis
Cytoplasmic division
Meiosis
Two-step reproductive cell division (reducing in half)
Cell cycle
When somatic cell duplicates its contents and divides in two
Diploid cells
Two sets of chromosomes
Haploid cell
Single set of chromosomes
Cell division phases
Interphase
mitotic phase
Interphase
Cell replicates it’s DNA
Produces additional organelles and cytosolic components
State of high metabolic activity
Mitotic phase
Results in the formation of two identical cells Nuclear division (mitosis) and cytoplasmic division (cytokinesis)
Three destinies of a cell
Remain alive and functioning
grow and divide
Die
Cdk’s
Enzymes that transfer a phosphate group from ATP to a protein to activate it
others remove phosphate group to deactivate
Aging
Progressive alteration of the bodies homeostatic adaptive responses
Geriatrics
Deals with medical problems and care of elderly
Gerontology
Study of the progress and problems associated with aging
Telemeres
Protect ends of chromosome