NBEO-Biochemistry (Non-Big 8)

Does the Rough Endoplasmic reticulum or smooth endoplasmic reticulum contain ribososome?

Rough Endoplasmic Reticulum

Where are gap junctions NOT found?

A) Heart

B) Cornea

C) Intraocular lens

D) Smooth muscle

B) Cornea

Which type of signaling involves the release of hormones that are carried to distant cells in the bloodstream?

A) Endocrine signaling

B) Paracrine signaling

C) Autocrine signaling

A) Endocrine signaling

Which type of signaling occurs when a signal molecule is released from one cell and acts on a neighboring cell such as a neurotransmitter?

A) Endocrine signaling

B) Paracrine signaling

C) Autocrine signaling

B) Paracrine signaling

Which type of signaling occurs when a cell responds to its own signal molecule such as T lymphocytes responding to their own growth factor?

A) Endocrine signaling

B) Paracrine signaling

C) Autocrine signaling

C) Autocrine signaling

Which of the following is considered the strongest type of chemical bond?

A) Covalent bonds

B) Electrostatic interactions

C) Hydrogen bonds

D) Van Der Waals interactions

A) Covalent bonds

For signal transduction, as adenyl cyclase increases, cAMP ____________.

cAMP increases (directly related)

Which type of receptor decreases adenyl cyclase and cAMP when it is stimulated?

A) Alpha 1

B) Alpha 2

C) Beta 1

D) Beta 2

B) Alpha 2

All proteins have ______________ in their structure.

A) PUFA

B) NH2

C) Helium

D) CO2

B) NH2

Which type of Amino Acids cannot be synthesized in the body and must be obtained from the diet? Essential or Non-essential?

Essential Amino Acids

Is glutamate considered an Essential or Non-essential amino acid?

Non-essential (it can be synthesized by the body)

_____________ Amino Acids yield Acetyl CoA when they are broken down.

A) Ketogenic

B) Glucogenic

A) Ketogenic

_____________ Amino Acids yield pyruvate when they are broken down.

A) Ketogenic

B) Glucogenic

B) Glucogenic

Multiple amino acids are linked together via a ______________ bond which is a covalent bond between an NH2 group and a COOH group found in proteins.

peptide bond

A peptide bond is found in which of the following?

A) Fats

B) Proteins

C) Carbohydrates

B) Proteins

Which of the following is a precursor for serotonin?

A) Arginine

B) Tryptophan

C) Tyrosine

D) Glycine

B) Tryptophan

Which of the following is a precursor for dopamine, epinephrine, and norepinephrine?

A) Arginine

B) Tryptophan

C) Tyrosine

D) Glycine

C) Tyrosine

Which of the following is a precursor for melanin?

A) Arginine

B) Tryptophan

C) Tyrosine

D) Glycine

C) Tyrosine

Albinism is a group of genetic disorders characterized by a mutation to an enzyme that is responsible for the conversion of _____________ to melanin.

A) Arginine

B) Tryptophan

C) Tyrosine

D) Glycine

C) Tyrosine

What is the precursor for Tyrosine?

Phenylalanine

What is the main function of the primary structure of an amino acid?

A) Amino acid sequence

B) Alpha helices and beta sheets

C) Globular structure

D) Fibrous structure

A) Amino acid sequence

Alpha helices and beta sheets are associated with which protein structural level?

A) Primary

B) Secondary

C) Tertiary

D) Quaternary

B) Secondary

Does albumin have a Globular or Fibrous tertiary protein structure?

Globular

Does collagen have a Globular or Fibrous tertiary protein structure?

Fibrous

Which structural level of proteins contains non-covalent and covalent disulfide bonds in order to form multimers?

A) Primary

B) Secondary

C) Tertiary

D) Quaternary

D) Quaternary

Proteins that serve as enzymes primarily function by lowering the _____________ energy needed to initiate a reaction.

activation energy

What is the first antibody made in response to an antigen?

IgM

What is the only antibody that is able to cross the placenta?

IgG

Which antibody is the most plentiful antibody in the body?

IgG

Which antibody is primarily found in tears, saliva, breast milk, and mucous membranes?

IgA

Which antibody is primarily involved with a Type 1 hypersensitivity reaction?

IgE

What is the most abundant protein found in the body?

Collagen

Which Vitamin is an essential cofactor for collagen synthesis?

A) Vitamin A

B) Vitamin B

C) Vitamin C

D) Vitamin D

C) Vitamin C

Which Amino Acid is NOT commonly found in collagen?

A) Glycine

B) Tyrosine

C) Proline

D) Lysine

B) Tyrosine

Collagen is a protein that has a _____________ helix in structure.

A) single helix

B) double helix

C) triple helix

D) penta helix

C) triple helix

Where is Type 1 collagen NOT primarily found?

A) Bones

B) Bowman's layer

C) Descemet's membrane

D) Corneal stroma

E) Sclera

C (Type 4)

What is the main type of collagen found in Descemet's membrane?

Type 4

What is the main type of collagen found in the vitreous?

Type 2

Osteogenesis imperfecta and Ehlers-Danlos syndrome primarily targets which type of collagen?

Type 1

Which of the following is NOT considered a collagen disorder?

A) Rheumatoid arthritis

B) SLE

C) Ehlers-Danlos syndrome

D) Ulcerative colitis

E) Osteogenesis imperfecta

D) Ulcerative colitis

Scurvy is a disease of weakened connective tissue and decreased collagen synthesis primarily caused by which vitamin deficiency?

Vitamin C

Which of the following is NOT true regarding hemoglobin?

A) It is responsible for transporting O2 to tissues throughout the body

B) It contains two alpha and two beta chains

C) Oxygen has a higher affinity for hemoglobin than carbon monoxide

D) It contains iron heme groups that bind to oxygen

C (higher for carbon monoxide)

_______________ is the concentration of the substrate when the rate of the reaction is 50% of Vmax in the Michaelis-Menten equation.

Km

When Km is high, does the enzyme have a low or high affinity for the substrate?

Low affinity

What is the linear graphical representation of the Michaelis Menten equation?

Lineweaver-Burk Plot

Which of the following is NOT true regarding the effect of competitive inhibition on a Lineweaver and Michaelis-Mentin Plot?

A) Vmax increases

B) Km increases

C) The x-intercept on the Lineweaver plot will shift to the right

D) Affinity between the enzyme and substrate decreases

A (stays the same)

Is Vmax unchanged in Competitive or Non-competitive inhibition?

Competitive inhibition

Is Km unchanged in Competitive or Non-competitive inhibition?

Non-competitive inhibition

Does competitive or non-competitive inhibition shift the Lineweaver-Burk plot to the right?

Competitive

Does Competitive inhibition shift the x-intercept of the Lineweaver-Burk plot to the Right or Left?

Right

Does Non-competitive inhibition shift the y-intercept of the Lineweaver-Burk plot Up or Down?

Up

What does Non-competitive inhibition do to Vmax?

Decreases

What does Competitive inhibition do to Vmax?

stays the same

What does Competitive inhibition do to Km?

Increases

What does Non-competitive inhibition do to Km?

Stays the same

Do Positive allosteric ligands cause the Lineweaver-Burk Plot to shift to the Left or Right?

Left

Do Negative allosteric ligands cause the Lineweaver-Burk Plot to shift to the Left or Right?

Right

Do Negative allosteric ligands increase or decrease Km?

Increase Km

Do Positive allosteric ligands increase or decrease Km?

Decrease Km

_______________ occurs when the binding of one substrate to the active site of an enzyme increases the affinity of the active site for additional identical substrate molecules.

Cooperativity

Which of the following is a common example of positive feedback?

A) Relationship between T4 and TSH

B) Release of oxytocin during child birth

C) Thermoregulation

D) Blood sugar regulation

B) Release of oxytocin during child birth

___________ is the amount of heat given off or absorbed in reaction.

A) Enthalpy

B) Entropy

A) Enthalpy (delta H)

___________ is the measure of disorder or randomness of a reaction.

A) Enthalpy

B) Entropy

B) Entropy (delta S)

Do Exergonic (-G) or Endergonic (+G) reactions release energy and occur spontaneously?

Exergonic (-G)

Is an exothermic reaction positive or negative?

Negative

Is an endothermic reaction positive or negative?

Positive

According to Gibbs free energy, will a spontaneous reaction more likely occur at a higher or lower temperature?

Higher temperature

Does delta G in Gibbs free energy provide information about the rate of the reaction or the direction of the reaction?

Direction of the reaction (NOT RATE)

If a substance loses electrons, does it become oxidized or reduced?

Oxidized (LEO)

If a substance gains electrons, does it become oxidized or reduced?

Reduced (GER)

Which of the following is NOT considered an important electron carrier in biological reactions?

A) NADH

B) FADH

C) NADPH

D) CO2

D) CO2

Which of the following electron carriers is primarily involved in the synthesis of cholesterol, fatty acids, and steroid?

A) NADH

B) FADH2

C) NADPH

C) NADPH

Which of the following electron carriers is primarily involved in the generation of ATP via the Krebs cycle? (Choose 2)

A) NADH

B) FADH2

C) NADPH

A and B

Do Acids donate or accept hydrogen ions?

Donate

Do bases donate or accept hydrogen ions?

Accept

pH + pOH= __________

A) 1

B) 7

C) 10

D) 14

D) 14

Is dihydrogen phosphate primarily an intracellular or extracellular buffer?

Intracellular

Is carbonic acid primarily an intracellular or extracellular buffer?

Extracellular

What are two main buffers found within the body? (Choose 2)

A) HCl

B) Dihydrogen phosphate

C) Carbonic acid

D) NaCl

B and C

What is the disaccharide glucose + glucose?

Maltose

What is the disaccharide glucose + galactose?

Lactose

What is the disaccharide glucose + fructose?

Sucrose

______________ is the storage form of glucose in plants.

Starch

____________ is the storage form of glucose in humans.

Glycogen

Which of the following are considered polysaccharides? (Choose 2)

A) Maltose

B) Starch

C) Glycogen

D) Sucrose

B and C

Which of the following are considered disaccharides? (Choose 2)

A) Maltose

B) Starch

C) Glycogen

D) Sucrose

A and D

Which of the following is NOT considered a polysaccharide?

A) Hyaluronic acid

B) Starch

C) Maltose

D) Keratan sulfate

C (disaccharide)

What is the main polysaccharide found in the vitreous?

Hyaluronic acid (GAGs= Polysaccharides)

What is the main polysaccharide found within the cornea?

Keratan sulfate (GAGs= Polysaccharides)

Do Proteoglycans or Glycoproteins have a larger carbohydrate component?

Proteoglycans

Glycolysis results in a net gain of __________ ATP and __________ NADH per glucose molecule.

2 ATP, 2 NADH

If oxygen is available, pyruvate is converted to __________ in order to enter the Krebs cycle.

Acetyl CoA

If oxygen is NOT available, pyruvate is converted to __________ for anaerobic glycolysis.

Lactic acid

The first reaction in the Krebs cycle is the conversion of Acetyl CoA to citric acid via which enzyme?

Citrate synthase

What is the major source of ATP in aerobic organisms?

A) Glycolysis

B) Krebs Cycle

C) Citric acid cycle

D) Oxidative phosphorylation

D) Oxidative phosphorylation

All of the following are mitochondrial DNA disorders associated with Electron Transport Chain and ATP synthesis except ______________.

A) Leber's hereditary optic neuropathy

B) Dominant optic atrophy

C) Stargardt's disease

D) Kearns-Sayre syndrome

C) Stargardt's disease

Oxidative phosphorylation (electron transport chain) produces __________ ATP per NADH and _____________ ATP per FADH2.

3 ATP per NADH, 2 ATP per FADH2

The total net ATP produced per glucose molecule during aerobic respiration (Glycolysis ---> ETC) is approximately ______________.

A) 20 ATP

B) 36 ATP

C) 50 ATP

D) 14 ATP

B) 36 ATP

What is the total amount of NADH produced by aerobic respiration (Glycolysis ----> ETC)?

10 NADH

What is the total amount of FADH2 produced by aerobic respiration (Glycolysis ---> ETC)?

2 FADH2