Lecture 2 - Cellular Anatomy Flashcards
Plasma Membrane
Forms the outer, limiting barrier separating the internal contents of the cell from the external environment
- Phospholipid bilayer
- Containing cholesterol and proteins (integral and peripheral)
- some Carbohydrates (externally)
- Contains receptors for communication
- Forms intercellular Connections
- Acts as physical barrier to enclose cell contents
- Regulates material movement into and out of cell
Cytoplasm
General term for all cellular contents located between the plasma membrane and the nucleus
Contains -
- Cytosol (Viscous fluid) (Gell like)
- Inclusions (Nonfunctional structures that store cellular products)
- Organelles (tiny structures that perform specific cellular functions) (Heterogeneous)
Place of many metabolic processes of the cell; stores nutrients and dissolved solutes
Cytosol
- Viscous fluid medium with dissolved solutes (Ions, nutrients, proteins, carbohydrates, lipids, and other small molecules)
- Provides support for organelles
- Serves as viscous medium through which diffusion can occur
Organelles
- Membrane bound and non membrane bound structures that have unique functions and activities
- **Carry out specific metablolic activites of the cell **
Inclusions
Nonfunctional, temporary structures that store cellular products
- Droplets of melanin, protein, glygocen granules, or lipid
- usually non membrane bound
- **Function - to store materials **
Nucleous
Surrounded by **double membrane nuclear envelope ** (2 membranes)
Each membrane is a phospholipid bilayer
Contains nucleoulus and chromatinm (strands of DNA)
Acts as cell control center
Controls protein synthesis (production of new proteins) so it directs the functional and structual characteristics of the cell
Controls all genetic info (DNA)
Site of ribosome subunit assembly
Nucleolus
Little
Ribosomal DNA is made
Ribosomal: site of translation (protein synthesis) using RNA
Nuclear envelope & nucleopores
Double membrane
2 processes….
1 - Making DNA from template (replication)…. DNA –> DNA
2 - Transcription DNA –> RNA (RNA goes through nucleopores to escape)
Membrane Bound Organelles
- Smooth Endoplasmic Reticulum (Smooth ER)
- Rough Endoplasmic Reticulum (rough ER)
- Golgi Apparatus
- Lysosomes
- Peroxisomes
- Mitochondria
Non - Membrane Bound Organneles
- Ribosomes
- Cytoskeleton
- Centrosome
- Cilia
- Flagellum
- Microvilli
Major Cell Components
- Plasma Membrane
- Cytoplasm
- Nucleus
Almost all human cells share the same 3 basic constituents
Smooth Endoplasmic Reticulum (smooth ER)
Interconnected newtowk of memrane tubules and cesicles
No ribosomes
Synthesizes lipids
Metabolizes carbs
Detoxifies drugs & alcohol
Like a folded up membonous bag
SINGLE complex membrane
contains proteins/ enzymes for specific cell functions
Rough Endoplasmic Reticulum (rough ER)
Flattened interacellular network of membrane sacs called cisternae
Ribosomes attached on cytoplasmic surface
Synthesizes proteins for secretion
New proteins for the plasma membrane
Lysosomal enzymes
Transports and stores molecules
Golgi Apparatus
Stacked series of flattened, smooth membrane sacs with associated transport vesicles (also called Shuttle Vesicles)
Modifies, packages, and sorts newly synthesized proteins for secretion
Inclusion in new plasma membrane, or lysosomal enzyme synthesis
Lysosomes
Membrane sacs with digestive enzymes
Digestive materials or microbes ingested by the cell
remove old/damaged organnels
self destruct (autolyze)
spherical structure
Lytic Enzymes
contain detox enzymes (breakdown toxic substances) - found in liver
Peroxisomes
Membrane - enclosed sacs
Usually contain large amonts of specific enzymes to break down harmful substances
Convert Hydrogen peroxide formed during metabolism to water
Mitochondria
Double membrane structures with cristae
Fluid matrix contents at center
Synthesize most ATP during cellular respiration
“Powerhouse of Cell” - if you see a lot of these, a lot of energy is used/needed
Contains enzymes needed for making ATP
Usually elongated cells
Aerobic respiration - oxygen is utilyzed (oxidative phosphorlation – produces ATP)
ADP+PO4 –> ATP
Ribosomes
Dense cytoplasmic granules with two subunits (large and small)
may be free in cytoplasm (free ribosomes) or bound to rough ER (fixed ribosomes)
Synthesize proteins for:
- Use in Cell (free ribosomes)
- Secretion, incorporation into plasma membrane, or lysosomes (fixed ribosomes)
Cytoskeleton
Organized network of protein filaments or hollow tubules throughout the cell
- Microfilaments
- Intermediate Filaments
- Microtubules
Microfilaments
Actin protein monomers formed into filaments
- Maintains cell shape
- Aid in muscle contraction and intercellular movement
- Separate dividing cells
Intermediate Filaments
Various Protein Components
Provide Structural support
Stabilze cell junctions
Microtubules
Hollow cylinders of tubulin protein
Able to strengthen and shorten
- Support cell
- hold organelles in place
- maintain cell shape and rigidity
- direct organelle movement within cell and cell motility as cilia and flagella
- move chromosomes at cell division
Centrosome
Amorphous region adjacent to nucleus
Contains a pair of centrioles
- Organizes microtubules
- participates in spindle formation during cell division
Centrioles
Paired perpendicular cylindrical bodies
Composed of microtubule triplets
- Organize microtubules during cell division for movement of chromosomes
Cilia
Short, membrane attached projections containing microtubles
occur in arge numbers on exposed membrane surfaces
Move fluid, mucus, and other material over the cell surface
Flagellum
Long, membrane attached projections containing microtubules
Occur in large numbers on exposed membrane surfaces
Propels sperms cells in human males
Microvilli
Numerous thin membrane folds projecting from the free cell surface
Increase membrane surface area for increased absorption and/ or secretion
Blood cell diameter
10 micrometers; (Book says 7-8)
Ovum Diameter
140 micrometers; (Book says 120) - Largest cell in body
Shape: Squamous
flattened, like a pancake/ fried egg
Shape: Cuboidal
Cube - all demensions are the same
Shape: Columnar
like a column
Shape: Stellate
Star shaped - multiple processes (Think 3D)
Shape: Ovoid
3D oval
Shape: Discoid
Disc/ Frisbee
Shape: Spindle
point on each end - football/ banana
Shape: elongated
…. elongated
Shape: irregular
No shape
Chemical Composition of Cells
Water, Electrolytes, Proteins, Carbohydrates, Lipid, Nucleic Acids
Chemical Composition of Cells - Water
75% water compatible with earths environment -Good solvent (many things soluble in it) -High Heat capacity (absorbs a lot of heat)
Chemical Composition of Cells - Electrolytes
Atoms joined by Ionic Bonds NaCl –> Na+ + Cl-
Chemical Composition of Cells - Proteins
Needed for cells to function made up of amino acids amino acids bonded together forming -peptide bond Peptide bonds forming Peptide chains of amino acids Peptide chains folded up forming a PROTEIN
Chemical Composition of Cells - Carbohydrates
Sugars(Gluclose) / Starches -Used to feul Cell - Form cell surface simple = monosaccharide (Just 1 glucose) glucose - glucose - fructose = polysaccharide (More than one)
Chemical Composition of Cells - Lipids
-Fats and Oils - Used for energy storage - Found in Membranes - Specific cells store lipids
Chemical Composition of Cells - Nucleic Acids
What forms the genetic codes
DNA
Deoxyribonucleic Acid what forms the genetic codes
RNA
Ribonucleic Acid used to make protein intermediate form
ATP
Adenosine Triphosphate The main currency in the cell when bond broken = energy is released Adenosin - PO4 - PO4 -/- PO4
All human cells share the same 3 basic constituents
Plasma Membrane, Cytoplasm, and Nucleus
Spindle in Cell Division
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