BCH 261 Lecture Notes - Lecture 2: Hydrogen Bond, Enzyme Catalysis, Amine

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cyansea-lion438

6 May 2016

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All proteins are hetorpolymers made up of 20 amino acids. *name, 3 letter code, and 1 letter code. The carboxyl and amino group can act as an acid or base this is known as amphoteric. At 7. 2 ph the carboxyl donates an h (so it is deprotonated) and the amino group accepts the h (so it is protonated). The amino acids are overall neutral, except for the r group, such ions are called zwitterions. At the ph amino acids are dipolar ions = zwitterions. If high ph, h is released, and the molecule becomes negatively charged. If low ph , h is acquired and molecule becomes positively charged. (cationic form) Therefore all amino acids have l- and d- enantiomers. In vitro: synthesis of amino acids: 1:1 ratio of l and d. In the cells: amino acids are predominantly of the l- enantiomer. At a ph of 2. 19: 50% will be in form 1 and 50% in form 2.

Related Questions

1. Compounds that are made of carbon, hydrogen, oxygen, nitrogenand/or sulfur are:

a. ionic compounds

b. molecular compounds

2. A peptide bond is a...

a. covalent bond

b. intermolecular force

3. In chemistry, what is an R group?

a. a real group

b. a free radical

c. Argon

d. a functional group

4. A hydrogen bond is a type of

a. dispersion force

b. dipole-dipole force

c. covalent bond

d. ion-dipole force

5. In general chemistry, what do weak acids do?

a. accept a proton

b. donate a proton

6. In general chemistry, what do weak bases do?

a. accept a proton

b. donate a proton

7. What happens to a weak acid when it donates a proton?

a. it becomes positively charged

b. it becomes negatively charged

c. it become neutral

8. what happens to a weak base when it accepts a proton?

a. it becomes positvely charged

b. it becomes negatively charged

c. it becomes neutral

9. R groups that cluster in the center of proteins or are foundadjacent to the hydrocarbon chains of membrane phospholipids tendto have R groups with alkyl groups, such as (âCH₃) or(âCH₂âCH₃). Using your General Chemistryknowledge, what bond, force or interaction would form between thesegroups?

a. chemical bond

b. hydrogen bond

c. van der waals interaction

d. covalent bond

10. A amino acid has an R group containing an amide group(âCONH₂), and another amino acid has an R groupcontaining a hydroxyl group (âOH). Using your General Chemistryknowledge, what bond or force would form between these groups?

a. chemical bond

b. hydrogen bond

c. van der waals interaction

d. covalent bond

tansea-lion662

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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