Introduction to cytology Flashcards
describe the cell theory
All _________ are composed of one or more cells.
Living organism
Cells are the smallest __________
structural/ functional unit of life
cells arise from_________
pre-existing cells.
How do we study cell structures?
Light microscopes and Electron microscopes
What type of microscope is this?
- Light passes through the specimen
- 0.2 micrometers resolving power( new advancement in computer image enhancement have enabled higher resolution with microscopes)
- Excellent for histology
- good to visualize the shape of cells and larger organelles
- multiple staining methods have been developed to improve contrast.
Light microscope
What type of microscope is this?
- Uses beams of electrons
- 0.2 nanometers resolving power ( 1000x higher than light microscopes)
- Scanning EM
- Transmission EM
Electron microscopes
_____ useful for cell surfaces, three-dimensional images
scanning EM
_____ Useful for exploring details of the internal structures of a cell and its organelles
Transmission EM
____ all cells vary in shape and functions but they all share general structures
Cell Diversity
What are the three main regions of cells:
Plasma membrane
cytoplasm
Nucleus
_____semipermeable barrier forming the outer border.
plasma membrane
_____ contents of the cell including organelles and a liquid called cytosol
cytoplasm
____intracellular fluid, contains ions, proteins, and nutrients.
cytosol
____ specialized cellular structures that perform a function.
What is one EX:
organelles
EX: nucleus
Can be a EX for Organelles. _____ contains the genetic material (DNA) that functions as instructions for making proteins.
nucleus
Size Range:
______Sensory neurons that extend from the tip of the toes to the brainstem
Longest cells (> 2 meters)
Size range
_____: Ovum (egg cell)
Largest cells (200 micrometers)
size range
____: Granule neurons in cerebellum and sprem
Smallest cells ( 4-5 micrometers)
What are the four common cell types?
Nervous tissue
Muscle tissue
Epithelia tissue
connective tissue
What tissue contains neurons and glial cells?
nervous tissue
what tissue contains muscle cells (a.k. a myocytes or fibers
Muscle tissue
what tissue contains epithelial cells?
epithelial tissue
What tissue contains mesenchymal cells ( Connective tissue stem cells), fibroblasts, fibrocytes, adipocytes (fat storage cells), chondrocytes ( mature cartilage cells), Osteocytes (mature bone cells ) Erythrocytes (red blood cells) Luekocytes ( white blood cells)?
Connective Tissues
_____ separates extracellular fluids ffrom intracellular fluid.
Plasma membrane
___ controls what enters and exits the cell
selective permeability
_______ cell recognition,binds hormones, cell communication
Cell markers and receptors
______ between other cell members or extracellular materials
Adhesion
What are the functions of the Plasma member?
Plasma member:
Selective permeability
cell markers and receptors
adhesion
What does the structure of the plasma membrane mean?
Fluid mosaic model
What is the plasma membrane made of?
Phospholipid bilayer
What are two type of phospholipid bilayer?
Hydrophilic heads and
hydrophobic tails
___ orient towards the extracellular and intracellular fluid
Hydrophilic heads
____ orient inward, away from the fluid
hydrophobic tails
What are the three different types of proteins?
- Peripheral membrane proteins
- Integral membrane proteins
- Channel proteins
____ functions as receptors, enzymes, and channels
Proteins
______ on the inside or outside of the member
Peripheral membrane proteins
____ embedded in the membrane
Integral membrane proteins
____ allows ions in/out of the cells
Channel proteins
What is the Plasma membrane composed of?
Phospholipid bilayer
Protiens
glycocalyx
Cholesterol
____ glycoproteins and glycolipds serve as biological markers for leukocytes of the immune system to recognize self Vs. non-self
Glycocalyx
____ stabilizes membrane
Cholesterol
_____ working cells must control the flow of materials between the Intracellular fluid- within the cell and Extracellular fluid- outside the cell
Plasma Membrane Transport
What are the four plasma membrane Transport?
Passive transport
Active transport
Endocytosis
Exocytosis
___ movement of solutes across a membrane DOES NOT require the cell to spend energy in the form of ATP.
Ex: Diffusion, and Osmosis
Passive transport
_____ requires energy (ATP) to move solutes across the membrane. Movement of solutes against the concentration gradient or very large molecules
Ex: Solute Pumping
Active Transport
______ proteins use ATP to transport solutes against concentration gradient
Example: Sodium-potassium pump
Solute Pumping
______Moves material from extracellular space into the interior of the cell
EX: Phagocytosis, Pinocytosis, Receptor mediated endocytosis
Endocytosis
___ cell takes in a large particle “ Cell is Eating”
Phagocytosis
___ cell takes in sample of extracellular fluid and small particles
“ Cell is drinking”
Pinocytosis
____ Cell is takes in particles with specific structures ( chemical shapes that called ligands than bind to receptors)
Receptor mediated endocytosis
_____ moves material from cell interior to the extracellular space. Vesicles fuse with the plasma membrane expelling the contents out of the cell.
Ex: Secreting enzymes, secreting pancreas enzymes
Exocytosis
_____ control center of the cell, contains chromosomes made of chromatin.
IN IT:
Chromatin, Nuclear envelope and the nucleolus
Nucleus
____ strands of DNA (genetic material) bound to proteins
Chromatin
___ double membrane separating the nucleus from the cytoplasm
Nuclear envelope ( a.k.a nuclear membrane )
___ dark stained body, site of ribosome production
Nucleolus
How does the central Dogma of genetics works?
DNA to MESSENGER RNA to PROTEIN
___ occurs in the nucleus the sequence of nucleotides in the DNA coding for a gene are read and used to guide the synthesis of a messenger RNA copy of the gene with a corresponding nucleotide sequence.
Transcription
___ occurs at ribosome when sequence of messenger RNA is read and used to guide the synthesis of a protein.
Translation
___ small dark bodies made of protein and RNA
- Site of protein synthesis (translation)
- found free in the cytoplasm and attached to rough endoplasmic reticulum
Ribosomes
_______ fluid- filled coiled tubules. serves as a channel for transporting substances within the cell.
Endoplasmic reticulumn (ER)
_______Er
- Studded with ribosomes
- manufactures all ssecreted proteins
Rough
____Er
*Functions in lipid metabolism and cell signaling
Smooth
____ Stack of flat membranous sacs
* packages proteins for transport depending on their final destination
Golgi apparatus
___ small membranous compartments bud off of the cell membrane,nucleus, ER, and Golgi apparatus
Vesicles
What are the three distinct pathways of vesicles:
Secretory vesicles
Membrane renewal vesicles
Become lysosomes or peroxisomes and remain in cytoplasm
What vesicle releases content by exocytosis?
Secretory vesicles
What vesicles fuses with cell membrane?
Membrane renewal vesicles
____ specialized vesicles containing proteolytic digestive enzymes
- Digest proteins from non-usable and damaged organelles
- Destroy bacteria and other foreign materials within the cell
Lysosome
____ specialized vesicles containing oxidase enzymes.
- Detoxify harmful substances like alcohol and formaldehyde
- Break down free radicals (highly reactive chemicals)
Peroxisome
____ double membrane structures
- Infoldings of inner membrane are called Cristae
- Inner fluid called the Matrix
- “Powerhouses” of the cell provides ATP for cellular energy
- Contains it’s own circular DNA for reproduction and protein synthesis
Mitochondrion
\_\_\_\_ " cell skeleton", provides the cell with an internal framework, support organelles, and facilliates intracellular motility. ***They are made of proteins Ex: Microtubules Microfilaments Intermediate filaments
Cytoskeleton
- Hollow tubes made of protein
- Radiate out from a region near the nucleus
- Anchor and move organelles
- form mitotic spindles during cell division
- Largest diameter of the “cell skeleton” elements
Microtubules
- Concentrated under the plasma membrane
- Function in cell mobility and shape
- Braces plasma membrane and strengthens cell surface
- Smallest diameter of the “cell skeleton” elements.
Microfilaments
- composed of proteins with high tensile strength
* resist pulling forces on the cell
Intermediate filaments
Where are centrosome located?
near the nucleus
centrosome directs what formation?
formation of microtubules
_____ have an important role in enabling the movement of chromosomes during cell division.
Centrosome
Centrosome consists of a pair of ______ - rod-shape bodies composed of short microtubles and other proteins arranged in a cylindrical structure.
Centriole
What are some extensions of the cell membrane?
Cilia
Flagella
Microvilli
____ whip-like extension that occurs on the free surface of the cell
- Move substances along cell surface
- Found on epithelial cells lining most of the respiratory tract
Cilia
____ similar whip-like extension but much longer
- Tail of sprem is only example in human anatomy
- Functions to propels the cell itself.
Flagella
___ small finger-like extension that increase surface area
*Found on epithelial cells lining the intestines and tubules of the kidney
Microvilli
_____ form an impermeable barrier between cells by interlocking proteins encircling the cell.
- Found at the apical surface of epithelial cells
- Keeps out enzymes, acids, microorganisms
Tight Junctions
____ Anchor intermediate filaments of adjacent cells together
Desmosome
___ cells are connected by hollow cylinders
- Allow chemical communication between cells
- Found in smooth and cardiac muscle
Gap junctions