Ch. 4 A Tour Of the Cell Flashcards
Electron microscope
Focuses a beam of electrons through a specimen or onto it’s surface
Transmission microscope
Used to study the internal structure of cells
Scanning electron mircroscope
Useful for detailed study of the topography o a specimen
Cell fractionation
A useful technique for studying cells structure and function
Plasma membrane
Selective barrier around a cell
Cytosol
A semifluid, jellylike substance
Chromosomes
Carry genes in the form of DNA
Ribosomes
Tiny complexes that make proteins according to instructions from the genes
Light microscope
Visible light is passed through the specimen and then through glass lenses
What are the characteristics that are only present in Prokaryotic Cells and Eukaryotic Cells?
Plasma membrane and ribosomes
What characteristics are Only Found in Eukaryotic Cells?
Membrane bound organelles in Cytosol and a nucleus
Where are prokaryotic cels found?
Domains bacteria and archaea
Where do Eukaryotic cells belong?
Domain Eukarya and include animals, fungi, plants, and Protists
What are three major details about Prokaryotes?
- Singular circular chromosomes in the Nucleoid region
- No membrane bound organelles
- Much smaller than Eukaryotes
Three major details about Eukaryotes
- Membrane enclosed nucleus contains the cell’s linear chromosomes
- many membrane bound organelles are in the cytoplasm
- larger than prokaryotes
Plasma membrane
Forms boundary for a cell
Plasma membrane made of …
Phospholipids, proteins, associated carbohydrates ( determine the function of the membrane)
Surface area to volume becomes less favorable as a cell ______ in size.
Increases
Organelles only found in animal cells
Lysosomes
Centrioles
Flagella (in some plant sperm)
Organelles only found in plant cells
Chloroplast
Central vacuole and tonoplast
Cell wall
Plasmodesmata
Endoplasmic Reticulum ( ER )
Membrane synthesis and metabolic processes
Rough Er
Ribosome- studded
Flagellum
Locomotion oraganelle present in some animals cells
Cell jobs…
- Building proteins( controls function)
- Make energy ( growth)
- Build more cells
Centrosomes
Microtubules are intiated, contains centrioles in animal cells
Microvilli
Projections that increase the cell’s surface area
Peroxisome
Produces hydrogen peroxide, transfers hydrogen from compounds of oxygen, break down fatty acids for mitochondria for fuel and detoxify alcohol by transferring hydrogen from the poison to oxygen
Mitochondrion
Cellular respiration occurs and most ATP is generated
Lysosome
Digestive organelle where macromolecules are hydrolyzed ( little stomach)
Cleans up broken down organelles ( clean up crew)
Apoptosis
Lysosomes break open & kill cells
ATP = \_\_\_\_\_\_ energy Carbohydrates = \_\_\_\_\_\_ energy
Active
Stored
Golgi apparatus
Active in synthesis, modification, sorting, and secretion of cell products
Ribosomes
Small dots that make proteins; free in cytoplasm
Nuclear envelope
Double membrane enclosing nucleus, continuous with rough ER
Nucleolus
Production of ribosomes
Chromatin
Material consisting of DNA and proteins
Cell wall
Outer layer of plant cell that maintains cell’s shape and protects cells from mechanical damage (made of cellulose, other polysaccharides, and protein)
Plasmodesmata
Channels through cell walls that connect the cytoplasm of adjacent cells
Chloroplast
Photosynthetic organelle, converts energy of sunlight to chemical energy stored in sugar molecules
Central vacuoles
Membrane bound vesicles, Functions in storage, breakdown of waste products, hydrolysis of macromolecules
Mitochondria contains …….
Inter membrane, outer membrane, inner member, cristae, matrix, DNA, free ribosomes
Cristae
Folds in mitochondria, increase surface area, enhancing productivity of cellular respiration
Mito. Matrix
Fluid filled and many of the reactions I celluar respiration occur here
Endosymbiont theory
Proposes that both mitochondria and chloroplasts share a similar orgin, organelles descended from prokaryotic cells once engulfed by ancestors of eukaryotic cells
Microtubules
Made of protein tubulin, largest of the cytoskeleton fibers
Support and shape the cell
Microfilaments
Composed of protein actin, movement
Intermediate filaments
More permanent fixtures in the cell, and fixing the position if certain oraganelles
Cilia
Used locomotion, lining of trachea moves mucus- trapped debris out of lungs
Extracellular Matrix ( ECM)
Composed of glycoproteins secreted by the cell, strengthens tissues and serves as a conduit for transmitting external stimuli into the cell/ turning genes on and modify biochemical activity
Tight junctions
Sections of an animal cell membrane where two neighboring cells fused, making the membranes watertight
Desmosomes
Fasten adjacent Animal cells together like strong sheets
Gap junctions
Provide channels between adjacent animal cells through which ions, sugars , communication molecules, and other small molecules can pass
Food vacuole
Phagocytosis, fuse with lysosomes
Contractile vacuoles
Maintain water balance in Paramecia and other Protists
Mitochondria = Chloroplast
Double membrane structure
Own ribosomes and circular DNA molecules
Reproduce independently within the cell
How is the Cell’s compartmental structure is crucial to it’s function?
The enzymes that produce hydrogen peroxide and those that dispose of toxic compounds are separate from the other cellular components that could be damaged
Chemical force
Ion’s concentration gradient
Voltage gradient
Attracts positively charged ions and repels negatively charged ions
Reception
The target cell’s digestion of a signal molecule coming from the outside
Transduction
The conversion of the signal to a form that can bring about a specific cellular response
Response
The specific cellular response to the signal molecule
Ligand
Binding between the signal molecule
Intracellular response
Found inside plasma membrane or nucleus, signal molecule must cross the plasma membrane and therefore must be hydrophobic, like steroid hormone testosterone
Plasma membrane receptors
Bind to water soluble Ligands
Phosphorylation cascade
Signal transduction pathways
Protein kinases
An enzyme that transfers phosphate group from ATP to a protein, signaling turn on
Protein phosphatases
Enzymes that remove phosphate groups and inactive protein kinases, signal turned off
Second messengers
Small, non protein water soluble molecules
Types of of second messengers
Calcium ions and cyclic AMP (cAMP)
Ligand gates ion channels
A membrane to open and close, regulating the flow of specific ions
