Chapter 1.2 Flashcards
What is the main difference between eukaryotic cells and prokaryotic cells
Eukaryotic
->they contain a true nucleus enclosed in a membrane
Prokaryotic
->they do not contain a TRUE nucleus
How do eukaryotic cells reproduce
-they reproduce through the process of mitosis
How many membranes in the nuclear membrane or envelope
-it is a double membrane
What allows for the selective two way exchange between the cytoplasm and the nucleus
-the nuclear pores allows for this
Describe the relation between histones and linear DNA
- linear DNA is bound around histone proteins
- >they are then wound around further to result in linear strands called chromosomes
Where is the ribsosomal RNA(rRNA) synthesized?
- it is synthesized in the nucleolus
- > the nucleolus is the darker spot in the nucleus
- > takes up about 25% of the nucleus
What is the function of the outer membrane of the mitochondria
-it serves as a barrier between the cytosol and the inner environment of the mitochondrion
What is the function of the inner membrane of the mitochondrion
- it is organized into foldings called cristae
- > contains molecules/enzymes necessary for the electron transport chain
-note the cristae increases the surface area available for the electron transport chain enzymes
What is the space between the inner and outer mitochondrion membranes
-this space is referred to as the intermembrane space
What is the space inside the inner mitochondrion membrane referred to as
-it is referred to as the matrix
What is meant by the term cytoplasmic inheritance or extranuclear inheritance? Give an example
- it is described as the genetic transmission of material independent of the nucleus
- > eg; mitochondria
What are lysosomes?
- they are membrane bound structures
- > containing hydrolytic enzymes
- > break down many substrates
What are endosomes and which organelles do they cooperate with
- they are organelles
- > that transport, package and sort cell material to and from the cell membrane
-they work together with the cell membrane, the TRANS golgi and the lysosomes for degradation
What is meant by the term autolysis? What does it ultimately result in?
- it is the release of enzymes from the lysosome
- > ultimately results in apoptosis
- > as there are hydrolytic enzymes
What is the smooth ER used for?
- they lack ribosomes
- > so they are used primarily for lipid synthesis
- > eg; phospholipids in the cell membrane
-they are also used for the detoxification of certain drugs and poisons
What are peroxisomes? What are their function
- they contain hydrogen peroxide
- > they primarily breakdown long chain fatty acids via BETA oxidation
- they are also involved in synthesis of phospholipids
- > contain some enzymes involved in the pentose phosphate pathway
What are the functions of the cytoskeleton? Also name the three types of cytoskeletons
- they provide structure to the cell and helps maintain the shape of the cell
- they also provide a conduit for the transport of materials around the cell
What are microfilaments? How do they help the cell? What are they made up of?
- they are made up of solid polymerized rods of actin
- > not hollow
- they help the cell with resistance of compression
- > they also provide protection for the cell
-actin works in unison with myosin as well to generate muscle movement
Do microfilaments play a role in cytokinesis
- yes
- > they are involved in the division of materials between daughter cells
- > they form the CLEAVAGE FURROW between two daughter cells
- > as actin within this cleavage furrow or ring contract, they become smaller
- > eventually pinching off the connection between the two daughter cells
What are microtubules? What are their functions in the cells
- they are hollow polymers of tubulin proteins
- >they provide pathways for kinesis and dynein to carry vesicles
Do cilia and flagella contain microtubules? What is their unique structure
- yes
- their unique structure is the 9+2 structure
- > 9 pairs of microtubules form the outer ring
- > 2 pairs of microtubules form the center
Where are centrioles found?What is their function during mitosis?
- centrioles are found in centrosomes
- > they are the organizing centers for mcirotubules
- during mitosis
- > they go to opposite poles of the cell and organize the mitotic spindle
- > they exert force on kinetochores this way, pulling the sister chromatids apart
What are different classes of intermediate filaments? What are they involved in?
- the different classes are keratin, desmin, vimentin and lamins
- they are involved in cell to cell adhesion
- they are also involved in maintaining the cytoskeleton integrity of the cell
- > allows the cell to withstand tension
- > making the cell structure more rigid
-they also anchor organelles organelles like the nucleus
What are the four tissue types
1) epithelial tissue
2) connective tissue
3) Muscle tissue
4) Nervous tissue
What do epithelial tissues cover? What functions does it serve
- they cover the body and line its cavities
- > provide a means against pathogen invasion or dessication
- they also are involved in
- > absorption, secretion and sensation
What are epithelial cells attached to
-they are attached to a connective tissue known as the basement membrane
What is meant by the parenchyma? Give examples
- they are the functional parts of the organ
- > the epithelia cells make up the parenchyma often times
- > eg; nephrons in the kidney, hepatocytes of the liver, etc
Are epithelial cells polarized? If so, then what is meant by the term polarized
- yes
- means one side faces the lumen
- > the other interacts with the underlying blood vessels/structural cells
-eg; small intestine cells
How to classify epithelia according to the number of layers
One layer
->simple epithelia
Multiple layers
->stratified epithelia
Multiple layers that seem to be different in height
->pseudostratified epithelia
How to classify epithelia according to their shape
- cuboidal
- columnar(long and thin)
- squamous(flat and scale like)
What are connective tissues used for
- they are used for:
- > supporting the body
- > providing the body with a framework for the eipthelia cells to carry out their functions
What is the main difference between epithelial cells and connective tissue cells
Connective tissue cells
- > main contributors to the stroma or support structure
- > eg; bone, cartilage, tendons, ligaments, adipose tissue and blood
Epithelial cells
->contribute to the parenchyma of an organ
Do cells in connective tissue secrete materials such as collagen and elastin
- yes
- >these materials form the extracellular matrix
