BSC 2010 Lecture Notes - Lecture 5: Lipid Bilayer, Peripheral Membrane Protein, Facilitated Diffusion

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cyanprairie-dog5

15 Feb 2016

School

University of Florida

Department

Biology - Biological Sciences

Course

BSC 2010

Professor

Chen Sixue

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Document Summary

Most lipids molecules are phospholipids with 2 regions. Hydrophilic- electrically charges heads that associate with water molecules. Hydrophobic- nonpolar fatty acid tails that do not dissolve in water: 2 important factors in membrane fluidity. Lipid composition- types of fatty acids can increase or decrease fluidity. Cholesterol and long-chain saturated fatty acids vs. unsaturated fatty acids with shorter chain. Temperature- membrane fluidity decreases in colder conditions: biological membranes contain proteins with varying ratios of phospholipids. Peripheral membrane proteins- lack hydrophobic groups and are not embedded in the bilayer. Integral membrane proteins- partly embedded in the phospholipid bilayer: anchored membrane proteins have lipid components that anchor them in, proteins are asymmetrically distributed on the inner and outer membrane the bilayer surfaces. Transmembrane protein- extends through the bilayer on both sides. May have different functions in its external and transmembrane domains. Some proteins can move within the phospholipid bilayer while others are restricted: proteins and cytoskeleton inside the cell can restrict movement of.

Related Questions

Which of the following Scientist(s) described the contemporaryâfluid- mosiacâmodel of the plasma Membrane
Davson and Nicholson
Nicholson and Danielle
Singer and Davson
Nicholson and Singer
Answer:_________________________________________________________________

________________________________________________________________________

The âfluid-mosaicâ model of the PM differ from the first proposedmodel in that:
The first model did not have cholesterol
The first model was devoid of some lipids
The first model was devoid of some proteins
The first mode was devoid of some carbohydrates
Answer:_________________________________________________________________

________________________________________________________________________

Which is most likely to be a membrane receptor protein?
A glycosylated protein containing three hydrophobic regions
A glycosylated protein devoid of hydrophobic regions
A protein containing hydrophobic regions but devoid of sugars
A glycosylated protein devoid of hydrophilic regions
Answer:_________________________________________________________________

________________________________________________________________________

Which secondary structures of proteins are formed within thePM?
Alpha-pleated sheets
Beta-pleated sheets
Alpha-helicies
Beta-helicies
Answer:_________________________________________________________________

________________________________________________________________________

Intergal proteins project
entirely outside of the bilayer on the extracellular surface
entirely through the membrane having N- and C- terminusexposed.
entirely outside of the bilayer on the cytoplasmic surface
outside bilayer but covalently linked to lipids withinmembrane
Answer:_________________________________________________________________

________________________________________________________________________

Which is the driving force which maintains the lipid bilayer?
Van der waals forces
Hydrophobic interactions
Hydrophilic interactions
Ionic interactions
Answer:_________________________________________________________________

________________________________________________________________________

What affect do lipids with double bonds in their nonpolar tailshave on the integrity of the PM?
They increase the fluidity of the PM
They decrease the fluidity of the PM
They allow more lipids to pack tighter in the membrane
They cause the membrane to become less stable
Answer:_________________________________________________________________

________________________________________________________________________

As the fluidity of the PM increases, what happens to theentropy?
increases
decreases
stays the same
none of the above
Answer:_________________________________________________________________

________________________________________________________________________

The consistency of membranes at various temperatures can beunderstood using the Margarine and Butter analogy. Butter containslonger saturated chains of fat derived from animals while Margarinecontains short polyunsaturated fats derived from corn oil. Whentaken directly from the refrigerator, Margarine can be spread withease while the Butter does not. What conclusion should you drawregarding how the composition of membrane lipid regulate thefluidity of the PM?
Longer chains exhibit more double bonds and increases contact oflipids
Longer chain exhibit fewer double bonds and increases contact oflipids
Shorter chains exhibit more double bonds and increases contact oflipids
Shorter chains exhibit more double bonds and increases contact oflipids
Answer:_________________________________________________________________

_____________________________________________________________________
Which PM lipid covalently anchors proteins?
Phosphoglycerides
Sphingolipids
Cholesterol
Triglycerides
Answer:_________________________________________________________________

________________________________________________________________________

Which PM lipid is the least amphipathic?
Phosphoglycerides
Sphingolipids
Cholesterol
Triglycerides
Answer:_________________________________________________________________

________________________________________________________________________

Which of the following is not a function of the PM?
Signal Transduction
Energy Transduction
Regulates which molecules enters and exits cell
Site of Biochemical events such as production ofmacromolecules
Answer:_________________________________________________________________

________________________________________________________________________

Which two PM phospholipids have negative charges?
Phosphatidylcholine and Phosphatidylethanolamine
Phosphatidylethanolamine and Phosphatidylserine
Phosphatidylinositol and Phosphatidylserine
Phosphatidylserine and Phosphatidylcholine
Answer:_________________________________________________________________

________________________________________________________________________

Which PM lipid is the only true glycolipid?
Phosphatidylcholine
Phosphatidylethanolamine
Sphingolipid
d. Cholesterol
Answer:_________________________________________________________________

________________________________________________________________________

Which is NOT a function of the Plasma Membrane
It serves as a barrier allowing all molecules to enter cell
It serves as a site for energy and signal transductions
It is composed of lipids, proteins, and carbohydrates
It compartmentalizes the cells
Answer:_________________________________________________________________

________________________________________________________________________

Cholesterol, which is not present in bacteria, controls the PMfluidity of animal cells. Which is the CORRECT orientation of thehydroxyl group of the four-member ring of cholesterol in thePM.
The hydroxyl group is oriented inside the membrane
The hydroxyl group is oriented toward the cytoplasm
The hydroxyl group is oriented toward other cholesterolmolecules
The hydroxyl group is oriented toward the membrane surface
Answer:_________________________________________________________________

_____________________________________________________________________
PM carbohydrates are oriented:
Inside the membrane
Toward the cytoplasm
Toward other carbohydrate molecules
Away from the cytoplasm and inside organelles
Answer:_________________________________________________________________

________________________________________________________________________

Sugars constituents various on red blood cells depending on bloodtype, why would giving someone the wrong blood type be fatal?
Blood groups differ in the levels of hemoglobin they carry
The body would view the sugars as antigens and form antibodiesagainst them.
Because of the incompatible sugar arrangement, the blood would notflow to the heart properly.
The foreign sugar sequences will attack to the sugar sequences onnormal cells.
Answer:_________________________________________________________________

________________________________________________________________________

NaCl most likely get into cells by which of the followingmethods?
Diffusion
Facilitated Transport
Osmosis
Active Transport
Answer:_________________________________________________________________

________________________________________________________________________

Sufferers of type II diabetes (adult onset) have normal insulinlevels but no target cell response due to deficiency in receptorsfor insulin. Which type of transport is missing?
Diffusion
Facilitated Transport
Osmosis
Active Transport
Answer:_________________________________________________________________

________________________________________________________________________

The movement of molecules against a gradient refers to which typeof transport?
Diffusion
Facilitated Transport
Osmosis
Active Transport
Answer:_________________________________________________________________

________________________________________________________________________

Which is the correct exchange of sodium and potassium in the Na/Kpump of cells?
three sodium for three potassium
two sodium for three potassium
three sodium for two potassium
two sodium for one potassium
Answer:_________________________________________________________________

________________________________________________________________________

This type of transport is important to cells because they receivetheir oxygen and rid themselves of carbon dioxide by thismethod:
Diffusion
Facilitated Transport
Osmosis
Active Transport
Answer:_________________________________________________________________

________________________________________________________________________

Maintaining membrane fluidity is important to cells because?
Cells are able to maintain proper function at differenttemperatures
Cells can break down membranes lipids very quickly when energy isneeded
Larger molecules can pass through the membrane when fluidity isincreased
The membrane fluidity helps to maintain the positions ofglycoproteins and glycolipids
Answer:_________________________________________________________________

________________________________________________________________________

Scientists agreed that the plasma membrane was the site ofbiochemical events when peroxide was broken to produce bubblescontaining?
water
hydrogen
oxygen
carbon dioxide

Answer:_________________________________________________________________

________________________________________________________________________

A set of erythrocytes is placed in a beaker of 0.9% NaCl.Nothing appears to happen to the cells. Why?

0.9% NaCl is hypertonic to the cells.

Sodium blocks the movement of water.

0.9% NaCl is hypotonic to the cells.

0.9% NaCl is iostonic to the cells.

water has not moved at all.

Question 2

Select one answer.

Which substance would be mostlikely to pass through a lipid bilayer/plasma membrane withoutembedded proteins?

water

a steroid hormone

a large fatty acid

a large peptide hormone

a sodium ion

Question 3

Select all that apply.

Which of the following can cross the cellâs plasmamembrane without the assistance of protein transporters?Select all that apply.

large polar molecules

positively charged ions

small hydrophobic molecules

gasses

Question 4

Select one answer.

Biological Membranesare:

symmetrical.

impermeable.

static.

dynamic.

Question 5

Select one answer.

How does the selectivepermeability of the membrane help the cell.

This allows the cell to maintain the proper shape.

This allows the cell to regulate what enters and exits

This allows the cell to maintain a constant temperature.

All of these

Question 6

Select one answer.

What is the role of carbohydratesin the plasma membrane?

cellular identification

adhesion

transport materials across the membrane

help maintain fluidity

Question 7

Select one answer.

Which component of the plasmamembrane has the widest variety of functions?

sterols

carbohydrates

phospholipids

proteins

Question 8

Select one answer.

All of the following have aneffect on the fluidity of a membrane except:

interactions among fatty acids in the core of the bilayer

the cholesterol content

the ratio of saturated to unsaturated fatty acids

the presence of integral proteins in the membrane

burgundyelk45

Question 401 pts

Kinetic energy is the stored energy that can be used for motion.

True

False

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Question 411 pts

When an electron is transferred from one atom to another, and the two atoms are then electrically attracted to one another, a(n) ________________ bond is formed.

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Question 421 pts

Changing the number of ____________ of an atom would change the chemical properties of the atom.

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Question 431 pts

Forming molecules and breaking down molecules in biological organisms usually requires the use of _________ to help the reaction proceed faster.

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Question 441 pts

Organic molecules have a core composed of .

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Question 451 pts

The building blocks of carbohydrates are

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Question 461 pts

Water molecules crossing a membrane from high to low concentration is .

active transport

cell fate

facilitated diffusion

osmosis

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Question 471 pts

Choose the membrane molecule responsible for the passage of polar molecules and ions into and out of the cell.

phospholipids

transmembrane channel proteins

cell surface proteins

carbohydrate chains

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Question 481 pts

The simplest cells are .

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Question 491 pts

Which of the following membrane bound organelles are found inside bacterial cells:

nucleus

organelles are not found in prokaryotic cells

mitochondria

chloroplasts

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Question 501 pts

Which of the following is a specialized components of the cell, is associated with the rough endoplasmic reticulum, and is responsible for making proteins.

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Question 511 pts

Proteins are sorted, modified, and packaged by the _____________ and later transported to the outside of the cell.

ribosomes

golgi bodies (golgi apparatus)

nucleus

mitochondria

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Question 521 pts

Dehydration synthesis is a process of linking two smaller subunits together to form a polymer. Which of the following statements below is true of dehydration synthesis?

Oxygen is consumed.

A water molecule is removed from the molecules.

A water molecule is added to the molecules

Carbon dioxide is given off.

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Question 531 pts

Proteins are made up of _________ held together by peptide bonds.

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Question 541 pts

Which of the following gives an amino acid its properties?

NH2

R Group or functional group

COOH

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Question 551 pts

The final three-dimensional shape of a protein that includes the bonding of two or more polypeptide chains is call its _____ structure.

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Question 561 pts

How do DNA and RNA differ?

all statements are differences between DNA and RNA.

DNA is double stranded while RNA is single stranded.

They have different sugars.

Thymine is present in DNA but not in RNA.

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Question 571 pts

Which of the following is a component of a DNA nucleotide?

phosphate

a nitrogen containing base

All are components of a nucleotide.

5-carbon sugar

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Question 581 pts

Cell membranes are made up of several different types of molecules. Select the membrane molecule below that is made up of a polar region and two non-polar fatty acid tails.

transmembrane proteins

carbohydrate chains

phospholipids

cell surface proteins

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Question 591 pts

Two organelles which are believed to have once been free-living bacterial cells are ____________ and ______________.

chloroplasts and mitochondria

golgi apparatus and endoplasmic reticulum

ribosomes and nucleolus

peroxisomes and lysosomes

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Question 601 pts

The is an extensive system of internal membranes responsible for producing carbohydrates and lipids.

smooth endoplasmic reticulum

rough endoplasmic reticulum

nucleolus

mitochondria

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BSC 2010 Lecture Notes - Lecture 5: Lipid Bilayer, Peripheral Membrane Protein, Facilitated Diffusion

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