BI110 Chapter Notes - Chapter 17: Ergosterol, Lipid Bilayer, Homeostasis

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pearyak445

9 Dec 2016

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The plasma membrane is key to making sure all components of a cell remain in place, to keep homeostasis. All membranes have a similar structure, however the functions depends on what proteins and lipids are making it up. The membrane binds to the cytoskeleton and ecm to maintain structure of the cell. The cell must not be soluble in water, so hydrophobic molecules like lipids are used to make it up. Amphipathic: contains both hydrophobic and hydrophilic regions, in this case a phospholipid. Micelle: when amphipathic molecules such as phospholipids are dropped in water, they form small groups called micelles that point all of the hydrophobic pats inwards, and all the hydrophilic parts outwards. This is why hen you put oil in water, you see many small drops of the old moving around instead of it dissolving evenly into the water.

Related Questions

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Osmosis (explain the role of aquaporins)

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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?

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raspberryraven266

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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