Font size
WorksheetsLIPCFI PRELIM QUIZ (SPECIAL)
Total questions: 93
Worksheet time: 1hrs 8mins
The central carbon atom in an amino acid is called:
β-carbon
γ-carbon
α-carbon
δ-carbon
What determines the unique chemical properties of an amino acid?
Amino group
Carboxyl group
Hydrogen atom
R group
At physiological pH (~7.4), amino acids exist predominantly in what form?
Protonated
Deprotonated
Zwitterionic
Neutral
Which amino acid is achiral?
Glycine
Alanine
Serine
Tryptophan
The amino acids serine, threonine, and cysteine are classified as:
Nonpolar
Polar, uncharged
Acidic
Basic
Which of the following is an aromatic amino acid?
Glycine
Phenylalanine
Leucine
Valine
The isoelectric point (pI) of an amino acid refers to:
The pH at which it is most acidic
The pH at which it is most basic
The pH at which it has no net charge
The pH at which it dissolves completely
Which amino acid contains a sulfur atom?
Methionine
Lysine
Aspartic acid
Histidine
Amino acids with positively charged side chains at physiological pH are:
Glutamine, Tyrosine
Aspartate, Glutamate
Lysine, Arginine, Histidine
Alanine, Glycine
Amino acids like leucine and valine are classified as:
Acidic
Nonpolar
Polar, uncharged
Aromatic
Which amino acid is often found in the active site of enzymes due to its imidazole ring?
Histidine
Proline
Serine
Tyrosine
Which of the following amino acids can form disulfide bonds?
Methionine
Cysteine
Serine
Threonine
What type of bonding occurs between amino acid side chains in protein folding?
Ionic
Hydrogen
Hydrophobic
All of the above
Which amino acid has the simplest structure?
Glycine
Proline
Valine
Alanine
What is the term for amino acids that the human body cannot synthesize and must be obtained from the diet?
Essential amino acids
Nonessential amino acids
Conditional amino acids
Aromatic amino acids
What is the main function of amino acids in the body?
Energy storage
Hormone synthesis
Building proteins
Catalyzing lipid breakdown
At acidic pH, the carboxyl group of an amino acid is:
Fully deprotonated
Partially deprotonated
Fully protonated
Neutral
Proline is unique among amino acids because:
It has an aromatic ring
Its R group forms a cyclic structure with the amino group
It contains a sulfur atom
It is achiral
What property makes polar amino acids soluble in water?
Hydrophobic interactions
Presence of hydrocarbon side chains
Ability to form hydrogen bonds
Absence of ionic groups
Which of the following amino acids is classified as acidic?
Arginine
Aspartic acid
Tyrosine
Cysteine
Which level of protein structure is determined by the sequence of amino acids?
Secondary
Tertiary
Quaternary
Primary
What type of bond stabilizes the α-helix and β-pleated sheet structures?
Covalent bond
Hydrogen bond
Ionic bond
Disulfide bond
The folding of a polypeptide into its three-dimensional shape is referred to as:
Primary structure
Secondary structure
Tertiary structure
Quaternary structure
Which amino acid is most likely involved in forming disulfide bonds?
Lysine
Glutamine
Cysteine
Proline
What is the primary driving force behind protein folding?
Hydrogen bonding
Hydrophobic interactions
Disulfide bonds
Ionic interactions
Denaturation of proteins disrupts all levels of structure except:
Primary structure
Secondary structure
Tertiary structure
Quaternary structure
The aggregation of multiple polypeptide chains into a functional protein is called:
Secondary structure
Tertiary structure
Quaternary structure
Primary structure
What happens to proteins when they are denatured?
Their amino acid sequence changes.
They lose their 3D structure but maintain their peptide bonds.
Their peptide bonds are broken.
Their primary structure is destroyed.
Which disease is associated with protein misfolding?
Diabetes
Alzheimer’s disease
Hypertension
Tuberculosis
What term describes a protein’s functional, folded 3D structure?
Native conformation
Denatured conformation
Zwitterion
Primary conformation
(a) is a type of protein structure formed when two or more polypeptide chains associate.
(a) an amino acid involved in forming disulfide bonds.
(a) is a type of interaction between nonpolar side chains during protein folding.
(a) is the term for protein unfolding caused by heat or chemicals.
(a) it is a secondary structure type often found in silk proteins.
Myoglobin’s primary function is to:
Store glucose
Transport oxygen in blood
Store oxygen in muscles
Act as an enzyme for digestion
The heme group in myoglobin and hemoglobin contains which metal ion necessary for oxygen binding?
Magnesium (Mg)
Iron (Fe)
Copper (Cu)
Zinc (Zn)
Which of the following best describes the structure of hemoglobin?
Globular and single subunit
Fibrous and multiple subunits
Globular and multiple subunits
Linear chain without subunits
What type of oxygen binding curve does hemoglobin display?
Hyperbolic
Sigmoidal
Linear
Exponential
The Bohr effect refers to:
The change in oxygen affinity of hemoglobin with changes in pH and CO2 levels
The binding of oxygen to myoglobin
The release of oxygen from myoglobin
The binding of oxygen to iron
The binding of oxygen to myoglobin is best described as:
Cooperative
Non-cooperative
Inhibitory
Competitive
Which of the following is a difference between myoglobin and hemoglobin?
Myoglobin has a lower affinity for oxygen than hemoglobin
Hemoglobin can bind to four oxygen molecules, while myoglobin can bind to only one
Myoglobin is more cooperative than hemoglobin
Hemoglobin is found only in muscles, while myoglobin is found in the blood
In the oxygen-binding curve of hemoglobin, the “sigmoidal” shape indicates:
Non-cooperative binding
Positive cooperative binding
Negative cooperative binding
No binding
The T-state of hemoglobin refers to the:
Oxygenated form
Deoxygenated form
Form that binds CO2
Form with the highest affinity for oxygen
Which factor promotes the transition of hemoglobin from the R-state to the T-state?
High oxygen concentration
Low pH (acidic conditions)
High temperature
Both b and c
What is the primary structural feature of fibrous proteins?
Globular shape
Extended, elongated structure
Random coil configuration
Tertiary folding
Collagen is primarily found in:
Blood plasma
Connective tissues
Skeletal muscles
Nervous tissue
Which amino acid is most abundant in collagen?
Lysine
Proline
Glycine
Histidine
Hydroxylation of proline and lysine in collagen requires which vitamin?
Vitamin A
Vitamin B12
Vitamin C
Vitamin D
What is the structural unit of collagen?
Fibrils
Triple helix
Alpha helix
Beta sheet
Which of the following diseases is caused by defective collagen synthesis?
Osteogenesis imperfecta
Scurvy
Ehlers-Danlos syndrome
All of the above
The elastic nature of elastin is due to its:
Cross-linked fibrils
Random coil structure
High glycine content
C Alpha helix conformation
What structural feature distinguishes keratin in hair from keratin in nails?
Disulfide bond density
Amino acid composition
Presence of glycine
Collagen content
Collagen forms fibrils by assembling into:
Alpha helices
Tropocollagen triple helices
Beta sheets
Globular domains
The main role of elastin is to:
Provide tensile strength
Resist compressive forces
Allow tissues to stretch and recoil
Prevent deformation under pressure
Which of the following is a non-standard amino acid unique to collagen?
Hydroxyproline
Selenocysteine
Ornithine
Cystine
Which process is disrupted in scurvy due to a lack of Vitamin C?
Cross-linking of collagen fibers
Triple helix formation
Hydroxylation of proline and lysine
Collagen degradation
Keratin belongs to which class of proteins?
Fibrous
Globular
Regulatory
Enzymatic
In which part of the body is Type I collagen primarily found?
Cartilage
Skin, tendons, and bones
Arteries
Basement membranes
What stabilizes collagen fibrils?
Hydrogen bonds and covalent cross-links
Peptide bonds
Ionic interactions
Disulfide bridges
Which amino acid contributes to the elasticity of elastin?
Proline
Glycine
Lysine
Desmosine
Which process is necessary for proper collagen fibril assembly?
Hydroxylation of lysine and proline
Phosphorylation of tyrosine
Carboxylation of glutamate
Sulfation of serine
Elastin is most abundant in which tissue type?
Tendons
Ligaments
Blood vessels
Skin
Which type of collagen is found in cartilage?
Type I
Type II
Type III
Type IV
What is the main difference between fibrous and globular proteins?
Fibrous proteins are soluble, globular are insoluble.
Fibrous proteins provide structure, globular have functional roles.
Fibrous proteins form enzymes, globular provide elasticity.
Fibrous proteins are spherical, globular are elongated.
What is the role of an enzyme in a chemical reaction?
It increases the energy required for the reaction to occur
It lowers the activation energy of the reaction
It decreases the rate of reaction
It is consumed during the reaction
Which of the following statements about enzymes is FALSE?
Enzymes are specific to the reactions they catalyze
Enzymes speed up chemical reactions
Enzymes are used up in the reaction
Enzymes are proteins with a specific three-dimensional structure
The Michaelis-Menten equation describes the relationship between the substrate concentration and the enzyme reaction rate. What does the term Vmax represent in this equation?
The rate at which the enzyme-substrate complex forms
The maximum velocity of the reaction when the enzyme is saturated with substrate
The rate at which the substrate concentration decreases
The concentration of substrate at half-maximal velocity
Which factor does NOT affect enzyme activity?
Temperature
pH
Enzyme concentration
Substrate color
What happens to enzyme activity as temperature increases?
It decreases linearly
It stays constant
It increases to a certain point and then decreases
It stops immediately
Which of the following is a product of the catalase reaction with hydrogen peroxide?
Carbon dioxide and water
Oxygen and water
Oxygen and hydrogen gas
Water and glucose
Enzyme saturation occurs when:
The enzyme concentration is too low
The substrate concentration is too high
All the enzyme molecules are bound to substrate molecules
The reaction rate decreases sharply
Which of the following is NOT a type of enzyme inhibition?
Competitive inhibition
Non-competitive inhibition
Substrate inhibition
Allosteric inhibition
Which statement describes a characteristic of a competitive inhibitor?
It binds to the enzyme’s active site
It changes the enzyme’s shape permanently
It reduces the concentration of the enzyme-substrate complex
It binds to an allosteric site
Which of the following would most likely increase the rate of an enzyme-catalyzed reaction?
Increasing the pH far above the enzyme’s optimum
Increasing the concentration of the substrate until the enzyme is saturated
Lowering the temperature below the enzyme’s optimum
Adding an enzyme inhibitor
Which of the following is the primary function of ATP?
To store genetic information
To provide chemical energy for cellular processes
To store oxygen
To transport electrons in metabolic reactions
Where is the majority of ATP produced in the cell?
Nucleus
Cytoplasm
Mitochondria
Golgi apparatus
The ATP cycle involves the conversion of ATP to ADP. What molecule is released during this conversion?
Oxygen
Water
Inorganic phosphate (Pi)
Carbon dioxide
What is the role of mitochondria in energy production?
They convert glucose into fatty acids
They synthesize proteins for energy production
They are the sites of aerobic respiration, producing ATP
They store energy in the form of glucose
Which of the following is a byproduct of oxidative phosphorylation?
Oxygen
Water
Carbon dioxide
Glucose
Which of the following processes produces the most ATP?
Glycolysis
Fermentation
Citric acid cycle
Electron transport chain and oxidative phosphorylation
Which molecule acts as the final electron acceptor in the electron transport chain?
Glucose
Oxygen
NADH
ADP
What happens during the process of chemiosmosis in the mitochondria?
Protons are pumped into the matrix of the mitochondria
ATP is synthesized as protons flow back through ATP synthase
Oxygen is used to break down glucose
Electrons are transferred from NADH to oxygen
How does the proton gradient created in the electron transport chain help produce ATP?
It generates electrical potential, which is used by ATP synthase
It drives the conversion of glucose to ATP
It breaks down glucose into smaller molecules
It produces water and carbon dioxide
Which of the following best describes the role of NADH in cellular respiration?
It provides oxygen to the mitochondria
It is used to transport electrons in the electron transport chain
It is a final product of the citric acid cycle
It is a byproduct of glycolysis
Describe the role of mitochondria in cellular respiration. Include the key processes that occur within the mitochondria and how they contribute to ATP production.
In Factors that affect enzyme activity.
Explain how temperature, pH, and substrate concentration influence the rate of enzyme-catalyzed reactions.
Compare and contrast aerobic respiration and anaerobic respiration.
Describe the differences between competitive and non-competitive inhibition.
Why did you choose LIPCFI?
What are your expectations in this Biochemistry Class?
Mention 3
What could be the possible reasons why you would not continue your chosen field? (BSN/BSPH)
Answer in 1 sentence only
Why do you want to become a nurse/ Pharmacist?
Mention your top 3 reasons
