Chapter 2 Flashcards
What are the three points of the cell theory?
- All organisms are composed of one or more cells
- The cell is the basic structural and functional unit of all living organisms
- Cells arise only from the division of pre-existing cells
What is the diameter of multicellular animal cells? Plant cells?
Animal- 5-30 um
Plant- 10- few hundred um
What are light microscopes?
Use light to illuminate a specimen
What is an electron microscope?
Use electron to view specimen
What is magnification?
The ratio of the object as viewed to its real size
What is resolution? How does wavelength affect resolution?
The minimum distance by which two points in the specimen can be separated and still be seen as two points
The shorter the wavelength, the better the resolution
Why are cells so small?
Surface area to volume ratio
Doubling the diameter of the cell multiplies it’s volume by 8 but multiplied it’s surface area by 4
Smaller the cell the less area to defend and less area to transport things across a cell
What does the cytoplasm contain?
Organelles
Cytosol
Cytoskeleton
What is the DNA containing central region of the cell in prokaryotes?
Nucleoid
What are ribosomes and their function?
They are small roughly spherical particles in the cytoplasm that use the information in the mRNA to assemble amino acids into to proteins
Site of protein synthesis
What coats the cell wall?
Layer of polysaccharides called
Glycocalyx
Capsule
What are pili?
Hairlike shafts of protein extending from cell walls
Function is to attach the cell to surfaces or other cells
What are the four groups of eukaryotes?
Protists, fungi, animals, and plants
What are lamins?
A network of protein filaments that line and reinforce the inner surface of the nuclear envelope
What is nucleoplasm?
The liquid or semi-liquid substance within the nucleus
Difference between chromatin and chromosome?
Chromatin is any collection of eukaryotic DNA with their associated proteins and chromosome is one complete DNA molecule with its associated proteins
What are golgi complexes?
Located near concentrations of rough ER membranes
Receive proteins that were made in ER and transported to the complex in vesicles
It regulates the movement of several types of proteins
What is exocytosis?
A secretary vesicle fuses with the plasma membrane and spills the vesicles contents to the outside
(Pushin out) exo
What is endocytosis?
Materials from the cell exterior are enclosed in a segment of the plasma membrane that pockets inward and pinched off as an endocytic vesicle
(Takes in)
What are lysosomes?
Small membrane bound vesicles that contain hydrolytic enzymes for the digestion of many complex molecules
Found only in animals
What is the lysosomes equivalent in plant cells?
The central vacuole fulfills the functions of the lysosomes in plant cells
What is phagocytosis?
A process in which some types of cells engulf bacteria or other cellular debris to break them down
What does cellular respiration start with and end with? Where does his take place in the mitochondria
Starts with energy rich molecules such as sugars, fats and other fuels that get broken down to water and carbon dioxide while producing energy
Takes place in the matrix and cristae
What is the function of the cytoskeleton?
Maintains the characteristic shape and internal organization of each type of cell through the interconnected system of protein fibres and tubes that extend throughout the cytoplasm
What are microtubules and microfilaments?
Microtubules are microscopic tubes that function like tubes engineers use to construct support structures
They also separate and move chromosomes driving cell division
Microfilaments are thin protein fibres that are involved in structural and locomotor functions
What are intermediate filaments?
Provide structural support in many cells (look at diagram of all three on page 42)
Where do cilia and flagella arise from?
Centrioles
What are chloroplasts, Amyoplasts and chromoplasts?
Chloro- site of photosynthesis
Amyo- colourless plastids that store starch
Chromo- contain red and yellow pigments and are responsible for colours of ripening fruits or autumn leaves
What is the thylakoids, granny and chlorophyll in chloroplasts?
Thylakoids- flattened closed sacs
Granum- stacks of thylakoids
Chlorophyll- a green pigment that is the primary molecule absorbing light
What is the tonoplast?
The membrane that surrounds the central vacuole
What is the plasmodesmata?
Perforates the cell wall with minute channels
What are cell adhesion molecules, cell junctions, and extracellular matrix?
Cell adhesion molecules bind cells together, more complex cell junctions seal the spaces between cells and provide direct communication between cells, and the extracellular matrix supports and protects cells and provides mechanical linkages
What are the three types of cell junctions common in animal tissue?
Anchoring junctions- form buttonlike spots that run around the cell welding adjacent cells together
Tight junctions- regions of tight connections between membranes of adjacent cells
Gap junction- opens direct channels that allow ions and small molecules to pass directly across cells
What is the ECM? What is the main component of it?
The extracellular Matrix provides protection and support and forms the mass of skin bones and tendons
Glycoproteins are the main component
