BIO1011 Lecture Notes - Lecture 6: Liposome, Cell Signaling, Membrane Protein

22 views4 pages

champagneseal760

14 Jun 2018

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

Lecture 6 - Cells and Membranes

Living things

● Are organised into cells

○ Prokaryotes and eukaryotes

● Must maintain an internal environment

○ Without barriers, life’s components would simply diffuse away

Prokaryote vs. Eukaryote

● Prokaryotes

○ Generally smaller

○ Bacteria are usually prokaryotes

○ Nucleoid (floating DNA)

○ Capsule

○ Circular DNA

○ Cell wall and cell membrane

● Eukaryotes

○ Usually larger

○ Membrane bound nucleus

○ Complex endomembranes

○ Linear DNA

○ Membrane-bound organelles

○ Plants also have cell wall and chloroplasts

Overview of membranes

● Water is polar

○ Oxygen molecule tends to drag electrons away from the hydrogen

● Main component of membrane is a phospholipid

○ Amphipathic molecule

○ Head is hydrophilic (charged), tail is hydrophobic (uncharged)

● The phospholipids arrange themselves into a bilayer sheet, a liposome or a

micelle

○ Initially a liposome that is a ring of tail-facing phospholipids containing

water in the centre

Membrane components - fluid mosaic model

● Fluid because phospholipids are moving around, not rigid

● Proteins embedded in the membrane is the mosaic component

Membrane structure & function

● Diverse phospholipids comprise the bilayer (omega 3 vs. omega 6 fatty acids

are used in a ratio to make up the bilayer)

● Other lipid components

○ Glycolipids - fatty acid with sugar (hydrophilic) attached used for cell-

cell signalling

○ Cholesterol - increases fluidity (at low temps) reduces fluidity - makes

find more resources at oneclass.com

Unlock document

This preview shows page 1 of the document.
Unlock all 4 pages and 3 million more documents.

Already have an account? Log in

Document Summary

Without barriers, life"s components would simply diffuse away. Plants also have cell wall and chloroplasts. Main component of membrane is a phospholipid. Oxygen molecule tends to drag electrons away from the hydrogen. Head is hydrophilic (charged), tail is hydrophobic (uncharged) The phospholipids arrange themselves into a bilayer sheet, a liposome or a micelle. Initially a liposome that is a ring of tail-facing phospholipids containing water in the centre. Fluid because phospholipids are moving around, not rigid. Proteins embedded in the membrane is the mosaic component. Diverse phospholipids comprise the bilayer (omega 3 vs. omega 6 fatty acids. Other lipid components are used in a ratio to make up the bilayer) Glycolipids - fatty acid with sugar (hydrophilic) attached used for cell- cell signalling. Cholesterol - increases fluidity (at low temps) reduces fluidity - makes stable (at high temps) Unsaturated tails stick out and pull membrane apart somewhat.

Related Questions

i need help with this homwork please choose the correct answers and just be claer to read and understand for the slect the apply qusestions too and it is important i realy need the right answers so please be claer not write randomly i really need the correct answers to study for my test so hop you can help me

Question 1

What is the smallest cell you could find?

Question 2

TEMs appear as 3D images

True

False

Question 3

Bacteria are what cell type? Write one word as the answer in lowercase and using no syntax.

Flag this Question

Question 42 pts

ALL eukaryotic cells have which of the following. Click all that apply.

membrane enclosed cell organelles

mitochondria

Question 5

Prokaryotes and eukaryotes both have which if the following cellular components. Click all that apply.

Question 6

I am made of one 60s and one 40s subunit, which organelle am I?

protein

lipid

bacterial ribosome

Question 9

The difference between the rough and smooth ER is

the rough produces lipids where as the smooth does not

the rough has many folds and convolutions where as the smooth does not

the rough has ribosome embedded and the smooth does not

the rough is closer to the cell membrane whereas the smooth is closer to the nucleus

Question 10

The site where many lipids, including cell membrane is produced.

Question 11

Name the organelle: In muscle cells in particular, I would increase in number and size in response to frequent exercise

Question 12

In animal cells, glucose would be mobilized from its storage molecule (glycogen) in this part of the cell.

Question 13

Which of these is associated with the rough ER

production of carbohydrates

production of steroid hormones

production of ATP

production of proteins that are secreted from the cell

Question 14

Which organelle sorts, modifies and stores substances produced on the rough ER. Write two words as the answer in lower case separated by a space.

Question 15

Which organelle is responsible for ATP production. Write one word in the singular as the answer.

Question 16

You inherit all of your mitochondria from your

father

half from your mother and half from your father

your siblings

mother

Question 17

An organelle that contains chlorophyll

Question 18

Microtubules have a variety of roles, which of the options below is NOT one of them?

separate chromosomes

cilia and flagellum movement

tracks for organelle movement

constrict the cell during cell division

Question 19

Made of tubulin subunits

microfilaments

chromosomes

intermediate filaments

microtubules

Question 20

Name the part of the cytoskeleton that is made of two twisted rods of actin. Write one word as the answer in lower case.

Question 21

Which part of the cytoskeleton is made of the same protein as your hair and nails?

microfilaments

microtubules

Intermediate filaments

Question 22

The extracellular matrix is found outside of, but attached to the cell membrane?

True

False

Question 23

Which of the options below is an important function of the extra cellular matrix?

connecting cells together

regulate the movement of substances into and out of the cell

helping cells divide into two cells

keeping the cell in a fixed and ridged shape

Question 24

Which part of the cell wall has a high pectin content?

Question 25

Plants have mitochondria, chloroplasts, a cell wall, and nuclei.

True

False

Question 27

What accounts for 40% of the protein in our bodies?

Question 28

Animal cells have cell walls

True

false

Question 401 pts

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

True

False

Flag this Question

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.

Flag this Question

Question 421 pts

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

Flag this Question

Question 431 pts

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

Flag this Question

Question 441 pts

Organic molecules have a core composed of .

Flag this Question

Question 451 pts

The building blocks of carbohydrates are

Flag this Question

Question 461 pts

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

active transport

cell fate

facilitated diffusion

osmosis

Flag this Question

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

Flag this Question

Question 481 pts

The simplest cells are .

Flag this Question

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

Flag this Question

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.

Flag this Question

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

Flag this Question

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.

Flag this Question

Question 531 pts

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

Flag this Question

Question 541 pts

Which of the following gives an amino acid its properties?

NH2

R Group or functional group

COOH

Flag this Question

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.

Flag this Question

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.

Flag this Question

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

Flag this Question

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

Flag this Question

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

Flag this Question

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

sangriarat617

________30. If you are investigating the inner structure of a new cell and see that it has a significantly larger amount of RER than other cells. You would conclude the cell does a great deal of____?
A. ATP synthesis

B. protein synthesis
C. DNA synthesis
D. active transport
E. polysaccharide hydrolysis

________31. If a cell comes in contact with a toxic substance such as H2O2, it could survive as long as it has a ___ to digest it.
A. DNA
B. peroxisome

C. mitochondria
D. phospholipids
E. intermediate filaments

________32. Some cells have structures to help them withstand osmotic pressure. For example,
A. Plant cells due to their walls
B. Animal cells due to the sodium/potassium pumps

C. Bacterial cell due to their swimming

D. Viruses due to their protein coats

________33. Evolution occurs only as a cell ____.

A. They undergo mitosis
B. Change in their gene pool
C. They move from one habitat to another

D. They begin to eat different foods

________34. Ribosomes are produced in the

A. nucleoli.
B. chromatin.
C. nuclear envelopes.

D. Golgi complex. E. cisternae.

________35. Algae are often green, but there are red and brown species also. What accounts for this difference in color?
A. The chlorophyll of chloroplasts
B. The pigments in other plastids

C. The presence of a mitochondria
D. The accumulation of cellular wastes

________36. The chloroplast and other like prokaryotes have which of the following that helps with photosynthesis?
A. They live in water based environments
B. They have chloroplasts in their cytoplasm

C. Change color in the dark vs. the sun
D. They have photoreceptor proteins in their membranes or mesosomes.

________37. Located in the membrane, we see a set of proteins called receptors that only connect with or bind to specific substances. This is called __.
A. ligand specificity.
B. hormone selectivity.

C. cell tonicity.
D. water saturation. E. signal resolution.

________38. Of the following statements, we could say that ___ is false.
A. All organisms are composed of cells and cell products.
B. An organism's structure and all of its functions are due to the activities of cells.
C. The cellular organelles are the simplest structural and functional unit of life.
D. Cells come from preexisting cells.
E. Cells are made from nonliving components including the nucleus, cell membrane and cytoplasm.

________39. If it is really true that our cells are the smallest anatomical unit that meets all of the properties of life, then which of the following could imply otherwise?
A. vacuoles
B. centrioles

C. Golgi apparatus
D. mitochondria
E. endoplasmic reticulum

________40. Oxygen is an absolute need for animal and plant cells alike due to the ___.

A. RER
B. Mitochondria
C. Lysosomes

D. DNA

________41. In a plasma membrane, we expect to see the carb/protein structures to extend into the ___, but the secondary messengers to move within the __.
A. extracellular fluid; cytosol
B. cytosol; extracellular fluid

C. intracellular fluid; cytosol

D. cytosol; intracellular fluid

E. extracellular fluid; plasma

________42. Bacteria are found in all of the following habitats:

A. Caves
B. Oceans
C. Animals

D. Everywhere on Earth

________43. Two solutions are separated by a selectively permeable membrane. Solution A has a higher concentration of an impermeable solute compared to solution B. Which of the following do you expect would happen?
A. solute will move from solution A to solution B

B. solute will move from solution B to solution A

C. water will more from solution A to solution B

D. water will move from solution B to solution A E. no movement of solute or water will occur

________44. In the kidney, we notice that almost all of the cells involved in the production of urine have high concentrations of the Na+/K+ pump. Which typically works to push Na+ ___ its concentration gradient by using ___.
A. up; active transport

B. up; facilitated transport
C. up; cotransport
D. down; active transport
E. down; facilitated transport

________45. In the charts of a patient recently admitted to the hospital noted that he was taking a medication called lithium and high doses of calcium supplements. Given this, we would expect the patientâs liver to have a higher than normal amount of __ to purify out the lithium and calcium.

A. lysosomes.
B. centrosomes.
C. mitochondria.
D. peroxisomes.
E. rough endoplasmic reticulum.

________46. We have long observed that our neural cells in the brain cannot replicate or replace themselves due to the lack of ____.
A. produce ATP.
B. divide.

C. produce enzymes.
D. secrete material across their plasma membrane E. conduct electrical signals.

________47. An organismâs structure and function is ultimately due to the structure and function of itâs __.
A. Organs
B. Tissues

C. Cells

D. Nuclei

BIO1011 Lecture Notes - Lecture 6: Liposome, Cell Signaling, Membrane Protein

Document Summary

Get access

Related textbook solutions

Molecular Cell Biology

Biology: Science for Life with Physiology

Biology

Concepts of Biology

Essentials of Biology

Related Documents

BIO1011 Lecture Notes - Lecture 6: Lipid Bilayer, Phospholipid, Nucleolus

BIO1011 Study Guide - Quiz Guide: Endomembrane System, Liposome, Electron Transport Chain

BIO1011 Lecture Notes - Lecture 6: Osmoregulation, Extracellular Fluid, Electrochemical Gradient

Related Questions