BIOL121 Lecture Notes - Lecture 1: Lipid Bilayer, Nuclear Pore, Nuclear Membrane

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13 Oct 2018

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1. 2 describe the composition and structure of the cell membrane, and explain how it acts as a selectively permeable barrier: a cell membrane is thin and semi permeable, consists of phospholipid bilayer with embedded proteins. It contains nuclear pores that allow for the exchange of material with the external environment. 1. 3 describe the functions of the cell membrane: selectively permeable in response to external environment. Microvilli: digestive system, finger like, increase surface area to allow food absorption. Cilia: respiratory system, moves materials across cell surface, removal of dust and germs inhaled form external environment. Flagellum: reproductive system, propels the cell ( ie sperm) 1. 4 distinguish between cytosol and cytoplasm: cytosol: the fluid that suspends other elements and particles, cytoplasm: material outside nucleus and inside cell membrane, organelles membrane bound, metabolic machinery of cell (ie the cytosol + the organelles) Control centre of the cells and contains the dna material. Three regio(cid:374)s (cid:373)ai(cid:374) regio(cid:374)s of the (cid:374)ucleus i(cid:374)cludi(cid:374)g .

Related Questions

Hybridomas are the useful result of a fusion between _______________ and _________________ to obtain hybrid cells that can proliferate and produce _________________ against specific ________________.

	myeloma cells; B lymphocytes; monoclonal antibodies; epitopes
	myeloma cells; T lymphocytes; polyclonal antibodies; antigen
	T lymphocytes; B lymphocytes; monoclonal antibodies; antigen
	T lymphocytes; B lymphocytes; polyclonal antibodies; epitopes

With respect to mammalian cell culture, which of the following statements is true?

	Media used for cell growth contain proteases and a divalent cation chelator to help cells adhere to the surface.
	During the establishment of a cell line, senescence is the last stage of the cell's life.
	Rodent cells cultures undergo spontaneous transformation with similar frequency to human cell cultures.
	Embryonic cell lines do not undergo senescence nor do they have a finite life span.

Epithelial cells have distinct surfaces. Which of these surfaces tends to be involved in secreting proteins out of the cell and into the bloodstream?

	apical
	basal
	All of the answers are correct.
	lateral

Which of the following is NOT true of phospholipid bilayers?

		Phospholipid bilayers separate the cell from the exterior environment as well as from compartments within the cell.
		The interior of phospholipid bilayers is a highly hydrophobic environment.
		Membrane budding requires transient breakages in the bilayer membrane.
		The chemical properties of phospholipids lead to the spontaneous formation of bilayers.

Which of the following is true regarding membrane proteins?

		All peripheral membrane proteins contact the lipid bilayer by covalent attachment to the hydrophilic head groups on membrane lipids.
		Beta strands can assemble into a membrane-spanning barrel structure.
		Lipid-anchored membrane proteins always face the cell exterior.
		A protein with six hydrophobic helices is most likely a lipid-anchored membrane protein.

Which of the following statements is NOT true?

		The three types of lipid anchors responsible for tethering proteins to the bilayer are acylation, prenylation, and ubiquitinylation.
		Movement of lipids from the cytoplasmic to the exoplasmic leaflet of the membrane bilayer requires specialized transport proteins called flippases.
		Glycoproteins are the basis for blood type compatibility between donor and receiver.
		Glycoproteins are always oriented so that the carbohydrate moieties are exoplasmic.

1 In our hierarchy of levels of organization (from atom to biosphere), at which level does life begin? Can you relate form to function when it comes to cell structure of a plant cell like Elodea? A thin simple squamous epithelium like in the lining of the lungs? A thicker columnar epithelial layer like that found in the stomach/intestine?

2. Can you remember the architecture of the phospholipid bilayer that makes up the cell membrane? How the 2 phospholipids arrange themselves to form the bilayer? And how you produce a water-proof (hydrophobic) barrier from the bilayer architecture?

3. What are the 3 roles of the plasma membrane? How does the barrier or âfenceâ role of the plasma membrane relate to non-polar vs. polar vs. charged molecules? How does the membrane control the amounts of certain molecules inside the cell? How does this relate to class rule #4? How do cells communicate with one another?

4. How does the plasma membrane help with this function? Which macromolecule is critical to this function? How does this all relate to red blood cells and âA/B/AB/Oâ blood type?

5. Can you explain how the phospholipid bilayer facilitates compartmentalization in a cell? What type of structures are compartmentalized? What is the value of compartmentalization in a cell?

raspberryraven266

Cells from which domain(s) of life are separated from theirenvironment by a plasma membrane? Select all correct choices.bacteria archaea eukarya 2. The active maintenance of a constantenvironment is referred to as: stability. homeostasis. symmetry.equilibrium. balance. 3. The electrical component of anelectrochemical gradient is due to: the use of ATP as an energysource to drive primary transport. a greater concentration ofpositive charges on the side of the membrane with the highestconcentration of protons. a greater concentration of positivecharges on the side of the membrane with the lowest concentrationof protons. a higher pH on the side of the membrane with the lowestconcentration of protons. a higher pH on the side of the membranewith the highest concentration of protons. 4. Which one of thefollowing would be found in the cells of a blade of grass but notin the cells of an insect feeding on that grass? Select all correctchoices. chloroplasts cytoskeletal elements mitochondriaendoplasmic reticulum nuclei 5. With which of the following is asignal-recognition particle (SRP) capable of interacting? Selectall correct choices. a signal sequence in a protein destined forthe ER a ribosome an SRP receptor 6. Which one of the followingcellular compartments does not have a double membrane structureseparating it from the rest of the cell? Select all correctchoices. mitochondria chloroplasts lysosomes the nucleus 7. True orFalse: purified phospholipids will gather together and formmembranes only if the appropriate enzyme is present. false true 8.Which component(s) of a phospholipid would most likely be found inthe interior of a lipid bilayer? Select all correct choices.glycerol fatty acids phosphate 9. Some drugs are now beingdelivered into cells through liposomes, where the drug issurrounded by a phospholipid bilayer. How do the drugs enter intothe cell? The liposome fuses with the phospholipid bilayer of thecell. The drug destroys the liposome and is transported viadiffusion into the cell. Protein channels on the cell surfacetransport the liposomes into the cell. The liposome cuts a hole inthe cell and injects the drug into the cell. 10. Some diseases canresult from defective transport across the membrane. For example,cystic fibrosis results from a chloride ion transporter that doesnot function. Which of the following would be affected when thistransporter does not function? the electrical gradient of the cellthe chloride concentration gradient Neither the chlorideconcentration gradient nor the electrical gradient of the cell Boththe chloride concentration gradient and the electrical gradient ofthe cell

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BIOL121 Lecture Notes - Lecture 1: Lipid Bilayer, Nuclear Pore, Nuclear Membrane

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