BISC 101 Lecture Notes - Lecture 1: Unsaturated Hydrocarbon, Lipid Bilayer, Alkane

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harlequinotter615

19 Oct 2015

School

Simon Fraser University

Department

Biological Sciences

Course

BISC 101

Professor

Ivona Mladenovic

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Document Summary

All cells are surrounded by a plasma membrane. There is a phospholipid bilayer that is created here in a way that there is a hydrophobic part (faces inside and away from water) and hydrophilic part (located outside). The membranes have two types of movements: lateral (neighbouring phospholipids will swap there places) and flipflop (two facing neighbours will change place) The lateral movement is rapid and happens often. Flip flop happens rarely (once per month) Fluid and viscous membranes. the composition of the phospholipids will be different. fluid= unsaturated hydrocarbon tails (more space= more fluidity) viscous= saturated hydrocarbon tails (tight, less room= more viscosity) Temperature: if exposed to different temperatures. high temperature= more viscous, low temp= more fluid. Presence of cholesterol: found in animal cell membranes. plant cells have some amounts but is negligible amounts. function= temperature buffer. reduces the fluidity at moderate temperatures and delays progress of solidification at colder temperatures.

Related Questions

I have this questions for my homework i need help with them look please it is important i need help so please give me the correct answers for each question and also please be clear to understand and aslo be correct it is very important becuase i need them so i really need the right answers. please help me and be correct and clear it is important ok

Question 5

At a constant temperature, if you increase the number of unsaturated fatty acid chains in the phospholipid, the membrane will become......

less fluid

more fluid

fluidity will be unchanged

Question 6

Bacteria in a hot spring at 80 degrees celsius would be expected to have ______________ in their cell membrane

high proportions of saturated phospholipids

high proportions of unsaturated phospholipids

an equal ratio of saturated to unsaturated phospholipid

Question 7

Membrane proteins have an important role in membrane fluidity

True

False

Question 8

The HIV virus can't attach to cells that have a mutation in the CCR5 gene and so such individuals are resistant to HIV. What population of people have a higher incidence of the mutant CCR5 gene and why?

europeans because their ancestors survived the bubonic plague

North Americans because their ancestors survived small pox

europeans because they have a longer evolutionary past with HIV

Africans because they have a longer evolutionary past with HIV

Question 9

Nematode trapping fungi have ______________ molecules called ______________ that recognize specific carbohydrates on the surface of the nematode worms. This is how a fungus can recognize that its prey, the nematode worm, has wriggled into the loop. Write two words on lowercase separated by a space with no other syntax

Question 10

Diffusion requires energy

True

False

Question 11

The net direction of molecule movement when molecules diffuse is

down their concentration gradient

random directions

Question 12

In osmosis, water molecules from a solution of higher solute concentration cross a semi-permeable membrane into a solution of lower solute concentration?

True

False

Question 13

Which best defines osmosis?

In osmosis, water from a solution of lower solute concentration move across a semi-permeable membrane into a solution of higher solute concentration?

In osmosis, water from a solution of higher solute concentration move across a semi-permeable membrane into a solution of lower solute concentration?

Question 14

Animal cells placed into a hypotonic solution would most likely?

lyse (burst)

shrink

remain unchanged in size

Question 15

Glucose and amino acids move into cells via carrier proteins, the same protein can move glucose or amino acids

True

False

Question 16

ATP powered pumps move substances into and out of cells by diffusion?

True

False

Question 17

For every 3 Na ions moved out, 2 K ions are moved into a cell by one cycle of the sodium-potassium pump.

True

False

Question 18

Bulk transport of fluid and any of the substances within that fluid is called

pinocytosis

phagocytosis

receptor-mediated endocytosis

exocytosis

Question 5

At a constant temperature, if you increase the number of unsaturated fatty acid chains in the phospholipid, the membrane will become......

less fluid

more fluid

fluidity will be unchanged

Question 6

Bacteria in a hot spring at 80 degrees celsius would be expected to have ______________ in their cell membrane

high proportions of saturated phospholipids

high proportions of unsaturated phospholipids

an equal ratio of saturated to unsaturated phospholipid

Question 7

Membrane proteins have an important role in membrane fluidity

True

False

Question 8

europeans because their ancestors survived the bubonic plague

North Americans because their ancestors survived small pox

europeans because they have a longer evolutionary past with HIV

Africans because they have a longer evolutionary past with HIV

Question 9

Question 10

Diffusion requires energy

True

False

Question 11

The net direction of molecule movement when molecules diffuse is

down their concentration gradient

random directions

Question 12

In osmosis, water molecules from a solution of higher solute concentration cross a semi-permeable membrane into a solution of lower solute concentration?

True

False

Question 13

Which best defines osmosis?

In osmosis, water from a solution of lower solute concentration move across a semi-permeable membrane into a solution of higher solute concentration?

In osmosis, water from a solution of higher solute concentration move across a semi-permeable membrane into a solution of lower solute concentration?

Question 14

Animal cells placed into a hypotonic solution would most likely?

lyse (burst)

shrink

remain unchanged in size

Question 15