Biochem Lab Final

0.01 M is equal to __ micro meters

0.01 × 10⁶ = 10,000

Assume you need 1 L 100 micro M glucose. How many grams of glucose do you need? MW of glucose = 180.2 g/mol

Define Stock Solution

Concentrated solution of a substance that is prepared in advance and diluted to a lower concentration for use in experiments or other applications. “Primary Solution.”

Define Aliquot

A portion of a larger whole, especially a sample taken for chemical analysis or other treatment. “portion of solution.”

How many mL of 1.5 M sucrose stock solution will you need to prepare 2 L of 250 mM sucrose solution?

pH stands for “the power of ______.”

Hydrogen

A buffer is a solution that can-

resist pH change.

Give an example to describe why proper pH of a system is important.

Blood; if pH rises or drops below physiological level (7.4), a person can get sick. Bicarbonate will neutralize excess acids while carbonic acid neutralizes excess bases to maintain a pH of 7.4.

Define buffer capacity.

The amount of strong acid or base that can be added to 1L of a buffer to change 1pH.

A buffer can be prepared by combining a weak acid and the salt of its-

conjugate base

What is an essential amino acid?

Amino acids that the human body cannot synthesize. Must be obtained from diet!

Name the functional groups common to all amino acids ________AND ________.

Amine (NH2) and Carboxyl (-COOH)

In today’s experiment (Characteristics of Amino Acids) migration rate will depend on the solubility of the _______.

Amino Acid.

Ninhydrin solution reacts with the _______ group of the amino acid to produce a purple color when heated.

amino

All naturally occurring amino acids are

L-enantiomers.

Coomassie G-2550 changes color when it interacts with amino acids. What color do you expect to see in samples with protein?

Blue

Describe the Bradford assay and why it is useful in biochemistry laboratories.

Colorimetric method to measure protein concentration (more intense blue = more protein concentration). Helps find casein protein in milk and how much is present. (Most sensitive)

What is the purpose for generating a standard curve plot in today’s experiment?

Absorbance of curve plotted against protein concentration. Formed dilution series of protein based on the blue intensity found in sample; used to observe casein concentration and absorbance comparison.

The most abundant protein in milk is 

Casein

Name the equipment you will use to collect absorbance data.

Spectrophotometer.

Name one amino acid in casein expected to react with the Coomassie dye in today’s experiment.

Arginine

The breakdown of cellulose produces ____ fuel.

Ethanol

In terms of a living system, which of the following is the most favorable method to increase the rate of a chemical reaction?

Use enzymes in the form of catalysts.

In today’s lab, which enzyme are we testing?

Cellobiase.

We will be using an artificial substrate to test our enzyme in today’s lab, rather than using the natural substrate. What is the artificial substrate?

P-nitrophenol glycopyranoside.

In today’s experiment the formation of product from the substrate will be indicated by a ______ color when it interacts with a basic solution.

Yellow

All of the following statements about carbohydrates is true EXCEPT?

No exception, all statements are true.

• Carbohydrates serve as the building blocks for structural compounds within living cells.

• Carbohydrates serve as an energy source.

• Carbohydrates have limited potential for mediating a variety of reactions.

• Carbohydrates have limited potential for carrying genetic information.

Carbohydrates are a diverse class of macromolecules with multiple hydroxyl as well as an aldehyde or _____ functional group.

Ketone

In today’s laboratory, we will be detecting different sugars. Name one of the monosaccharides we will be investigate ________.

Glucose.

Benedict’s test detects:

sugars that are reducing sugars.

Which of the following answers best describes how we can determine if sucrose is in our unknown sample?

Hydrolyze the glycosidic bond to break it down in its monosaccharides and then use Seliwanoff’s test.

Based on the Figure 1 on pg 68 of your lab manual, what are the reactants and products of a catabolic process.

Reactants = Large biological molecules

Products = small building blocks + ATP

Based on the Figure 1 on pg 68 of your lab manual, what are the reactants and products of an anabolic process?

Small building blocks + ATP = Large biological molecules

Reactions of catabolism are?

Exergonic because breaking down biomolecules release Gibbs free energy.

Anabolic reactions are?

Endergonic because forming biomolecules requires Gibbs free energy.

Metabolism is best defined as?

The sum of all chemical reactions that occur within a living system, including both energy-releasing and energy-consuming pathways.

Eating a large meal followed by NO exercise:

Glycogen synthesis

Depletion of glycogen stores:

Gluconeogenesis

Fasting (low blood glucose):

Glycogenolysis

During high intensity exercise after a meal:

Glcolysis

Scenario:

After eating. a large pasta dinner and dessert, glucose begin stop enter the liver and adipose cells. Inside the liver, acetyl-CoA molecules start combining to be stored for later use.

Question:

Is the primary process described here anabolic or catabolic?

Anabolic

Scenario:

After eating. a large pasta dinner and dessert, glucose begin stop enter the liver and adipose cells. Inside the liver, acetyl-CoA molecules start combining to be stored for later use.

Question:

Which two energy carriers are likely involved?

• NADPH

• ATP

Scenario:

After eating. a large pasta dinner and dessert, glucose begin stop enter the liver and adipose cells. Inside the liver, acetyl-CoA molecules start combining to be stored for later use.

Question:

Which molecule is being synthesized for storage?

Fatty acids

Scenario:

A student wakes up early and goes for a fasted 5-mile run before breakfast. Because they have not eaten since dinner, blood glucose levels begin to drop. In response, the pancreas releases glucagon and epinephrine, signaling liver and muscle cells to mobilize stored energy.

Question:

Is the overall metabolic process anabolic or catabolic?

Catabolic

Scenario:

A student wakes up early and goes for a fasted 5-mile run before breakfast. Because they have not eaten since dinner, blood glucose levels begin to drop. In response, the pancreas releases glucagon and epinephrine, signaling liver and muscle cells to mobilize stored energy.

Question:

Identify two pathways activated by this scenario:

• Glycogenolysis

• Glycolysis

Scenario:

A student wakes up early and goes for a fasted 5-mile run before breakfast. Because they have not eaten since dinner, blood glucose levels begin to drop. In response, the pancreas releases glucagon and epinephrine, signaling liver and muscle cells to mobilize stored energy.

Question:

Which hormones have signaled the activation of these pathways?

• Epinephrine

• Glucagon

At the end of glucose catabolism, where did the six carbons from glucose go?

converted into 2 pyruvate

How many ATP are directly generated by the catabolism of one molecule of glucose?

2 ATP

Common culture says “too much sugar makes you fat.” If carbohydrates and fats are structurally different molecules, explain how eating too much sugar could make you fat.

Too much sugar means too much glucose which then gets converted into acetyl-CoA which is used to make fatty acids. Which are then stored as fats hence “making you fat.”

Provide the name of the process that describes the synthesis of glucose:

Gluconeogenesis

Name the molecule containing three carbons that can be used by the body to make glucose:

Pyruvate

Which of the following do you think would provide glucose the quickest when the body needs it? Polysaccharides, proteins, or fats?

Polysaccharides

When pyruvate is used to form acetyl-CoA, the product has only two carbon atoms. What happened to the third carbon atom?

The 3rd carbon was released as CO2.

What products of the citric acid cycle are used in the electron transport chain?

• NADH

• FADH2

Low carbohydrate diets can temporarily lead to weight loss because the body does not store carbohydrates. Name the storage form of carbohydrate in the body. What do you think will happen when carbohydrates are reintroduced to the diet?

Carbohydrate storage = glycogen

When introduced to the diet, they will either be stored (glycogen synthesis) if inactive, or utilized (glycolysis) for energy if active.

Label the following into the two groups: 1) Fed State or 2) Fasting State

Insulin is high

Fed State

Label the following into the two groups: 1) Fed State or 2) Fasting State

Epinephrine is high

Fasting State

Label the following into the two groups: 1) Fed State or 2) Fasting State

Fat is stored

Fed State

Label the following into the two groups: 1) Fed State or 2) Fasting State

Fat is released

Fasting State

Label the following into the two groups: 1) Fed State or 2) Fasting State

Lypolysis is active

Fasting State

Rank the following steps in the correct order (1-4):

• Travels the blood bound to proteins

• Fatty acid leaves adipose tissue

• Arrives in mitochondria

• Enters the cell

1. Fatty acid leaves adipose tissue

2. Travels the blood bound to proteins

3. Enters the cell

4. Arrives in mitochondria

Idea:

Fat enter mitochondria

Meaning:

Fat reaches the cell’s energy factory

Idea:

Fat is cut into smaller pieces

Meaning:

Can be used to make energy

Idea:

ATP is made

Meaning:

Cell gets usable energy

How is the fatty acyl CoA at the top of the cycle different from the fatty acyl CoA at the bottom of the cycle?

The fatty acyl CoA at the top has 2 MORE carbons than the fatty acyl at the bottom. (top = 18C; bottom = 16C)

How many acetyl-CoA molecules are produced in one cycle of beta-oxidation?

1 acetyl-CoA is produced per cycle.

How many reduced electron carriers are produced in one cycle of beta-oxidation? Name them:

• FADH2 (1)

• NADH + H+ (1)

How many cycles of beta-oxidation would it take to catabolize the entire fatty chain in acetyl-CoA molecules?

Number of cycles = n (# of carbons)/2 -1 = 

8 cycles

How many acetyl-CoA molecules would be produced total if the entire fatty chain is catabolized?

9 acetyl-CoA molecules

How many reduced electron carriers would be produced total if the entire fatty chain is catabolized?

16 reduced electron carriers

(8 FADH2, 8 NADH +H+)

Fat is mainly stored in?

adipose tissue

Which hormone triggers fat breakdown during fasting?

Glucagon

Where does beta-oxidation occur?

Mitochondria

When insulin is high, the body will:

Stores fat

Fat travels in the blood by attaching to

Proteins

Which organelle is the energy factory of the cell?

Mitochondria

The main energy molecule produced is?

ATP