EVALS AND TERM EXAMS (2020) Flashcards
Which of the following describes digestion?
A. Hydrolize chemical bonds
B. Uptakes micronutrients by enterocytes
A. Hydrolize chemical bonds
What digests carbohydrates
A. Amylase
B. Lipase
C. Protease
A. Amylase
What is the role of chylomicrons in lipid digestion?
A. Its hydrophobic tail allows … to interact with the lipid environment of the enterocyte
B. It allows … to travel through the lacteals
C. It breaks down large globules to small lobules
B. It allows … to travel through the lacteals
Not a role of saliva?
A. Lubrication
B. Denaturation
C. Digestion
D. Ease on swallowing
B. Denaturation
Most enzyme … in high temperature
Denaturation
Diacylglycerols are broken down into monoacylglycerol and free fatty acids by hydrolysis of what ester bonds?
A. SN1 and SN2 ester bonds
B. SN2 and SN3 ester bonds
C. SN1 and SN3 ester bonds
D. SN3 ester bond only
C. SN1 and SN3 ester bonds
Which is not part of catalytic triad of lingual lipase?
A. Asparagine
B. Histidine
C. Serine
D. Aspartate
A. Asparagine
Enzyme increase?
A. By altering the …
B. Bind to substrates
C. Increasing molecular collision frequency
NO ANSWER
Absorbed in the duodenum
Fe(Iron)
Segregation of metabolic pathways ensuring metabolic efficiency is made possible by:
A. Michaelis Menten Kinetic Theory
B. Collision Theory
C. Equilibrium Constant
D. Compartmentation
D. Compartmentation
Transfer groups between atoms within a molecule
Mutase
Michaelis menten, high concentration
Zero Order
Region of substrate attachment
Active Site
Which of the following is true about pepsin?
A. Secreted by gastric parietal cells
B. Secreted as proenzymes
C. Denaturation of protein
C. Denaturation of protein
Transport molecule from an area of higher to lower concentration with the use of transport of protein is called?
A. Carrier mediated diffusion/Facilitated diffusion
B. Active transport
C. Secondary active transport
D. Passive diffusion
A. Carrier mediated diffusion/Facilitated diffusion
Alcohol absorption
A. Active transport
B. Secondary active transport
C. Passive diffusion
D. Osmosis
C. Passive diffusion
What is the mechanism behind the action of Lingual Lipase?
A. Hydrolysis of SN1 ester bonds
B. Hydrolysis of SN2 ester bonds
C. Hydrolysis of SN3 ester bonds
D. Hydrolysis of SN4 ester bonds
C. Hydrolysis of SN3 ester bonds
What is necessary prior go lipid digestion?
A. Unfolding of the lipid globules into long triglycerides
B. Breaking down of large lipid globules into several small lipid globules
C.
D. Activation of lipases to hydrolyze lipid globules into FFA
B. Breaking down of large lipid globules into several small lipid globules
Hydrolysis by lingual lipase yields what?
Diacylglycerol (DAG) and free fatty acids
Absorption of water
Osmosis
Which of the following statements are true?
Enzymes are truly selective catalysis
What will determine the rate of chemical reaction will proceed?
A. Speed
B. Magnitude
C. Equilibrium Constant
D. Speed and Magnitude
B. Magnitude
If free energy is lower than substrate (negative)
Left to Right
In michaelis menten kinetic theory, if the substrate concentration is higher than the enzyme concentration what would happen?
Something about saturated and enzymes tas excess ang substrate…
Enzyme differ with other inorganic substances because they
Not consumed in the reaction
What is necessary prior to lipid digestion
Break down of large lipid globules into several small lipid globules
Small Km
Lower concentration of the substrate is needed to half-saturate the enzyme
Lactase deficiency lacks ability to break down into:
Glucose + Galactose
Which of the following describes iron absorption?
A. An oxidizing agent is needed to increase iron absorption such as vitamin C
B. In iron deficiency, more hepcidin is synthesized to increase iron absorption
C. Absorption of iron is limited due to the formation of iron free radicals
D. Primary site of iron absorption is jejunum
C. Absorption of iron is limited due to the formation of iron free radicals
Overall digestion of protein starts in what organ?
Stomach
Salivary amylase not active in the stomach because
A. Inactivated by pepsin
B. Inactivated by acid
B. Inactivated by acid
What does salivary amylase hydrolyse?
A. a-1,4 of amylose
B. a-1,4 of amylopectin
C. b-1,4 of amylose
D. b-1,4 of amylopectin
A. a-1,4 of amylose
How does amylase “digest” starch?
A. Hydrolyzing amylose ???
B. Hydrolyzing amylopectin
C. Breaking ester bond of Alpha(1-4)
D. Breaking ester bond of Alpha(1-6)
A. Hydrolyzing amylose ???
2 factors always measured when dealing with enzymes
Km and Vmax
Effects of competitive inhibitor on the kinetics of enzyme reaction except:
A. Increase concentration of substrate reverses the inhibition
B. The inhibitor binds to a site on the enzyme other than the catalytic site
C. Km is increased
D. Kcat no change
B. The inhibitor binds to a site on the enzyme other than the catalytic site
Hydolyzes peptide bonds FROM THE ENDS of peptides
A. Carboxypeptidase
B. Elastase
C. Chymotrypsin
D. Pepsin
A. Carboxypeptidase
True of Go, except:
A. Independent of the mechanism of reaction
B. Provide information only about direction and equilibrium
C. Provide no information concerning the reaction rate
D. Provide information about direction, equilibrium and reaction rates
D. Provide information about direction, equilibrium and reaction rates
What does the effect of pH on an enzyme catalyzed reaction reflect?
A. Denaturation of the enzyme
B. Ionization of the product
C. Esterification of the enzyme
D. Dephosphorylation of the product
B. Ionization of the product
Co-transport/Secondary active transport
Movement of one molecule down its concentration gradient (higher to lower) to power movement of another from lower to higher
Acid enters the duodenum:
Secretin is released
Inferred from the presence of amino acids in the same position in the family group
A. Reserve residues
B. Conserved residues
C. Conservative residues
D. Preserved residues
B. Conserved residues
State at which molecules may equal with probability to go ahead to products or go back to reactants:
Transition state
Anything that increases the frequency of collision will increase the rate of reaction:
Kinetic theory
Substrate is proportional to product:
Mixed order
Distinct enzyme reaction that catalyze same reaction arise through gene duplication:
A. Lysozyme
B. Residue
C. Homologous
D. Isoenzyme
D. Isoenzyme
Determines how far the reaction will go
Magnitude of free energy
Salivary amylase does not contribute yo the digestion of carbohydrates on the stomach because _____ inhibits salivary amylase
A. Pepsin
B. Peristalsis
C. High pH
D. Chief Cells
D. Chief Cells (production of HCl inactivates salivary amylase)
Mechanical digestion in small intestine
A. Chyme is propelled caudally to mix with digestive enzymes
B. Segmented longitudinal muscles contract and relax
C. Circular muscles contract and relax
D. Segmentation … slowing overall process
A. Chyme is propelled caudally to mix with digestive enzymes (Peristalsis)
MAG and FFA hydrolyzed by
SN1 and SN3
If Go is negative
Reaction is left to right
Digestion includes
Hydrolysis of chemical bonds
Distinct enzyme forms that catalyze the same reaction arise through gene duplication
A. Lysozymes
B. Residue
C. Homologous
D. Isozyme
D. Isozyme
Small Km
A. Low concentration of substrate is need to half saturate the enzyme
B. Low affinity of enzyme to substrate
C. High affinity of enzyme to product
D. High concentration of substrate is needed to half saturate an enzyme
A. Low concentration of substrate is need to half saturate the enzyme
Catalytic triad except
Asparagine
Lactose
1 Glucose + 1 Galactose
In michaelis menten, at high concentrations of substrates, the velocity of the reaction is
Zero order kinetics
Alcohol
Passive diffusion
Sigmoid graph
Cooperative binding
*** FIGURE
of oxygenase
Heme to biliverdin
Transition state
The state from which molecules may with equal probability go ahead to products or back to reactants
Absorbed in the duodenum
Iron
Water absorption
Osmosis
Exopeptidase that hydrolyze peptide bonds from the ends of peptides
Carboxypeptides
Effect of noncompetitive inhibition except
A. Cannot be overcome by increasing the concentration of substrate
B. Increase Vmax
C. Km is unchanged
D.
B. Increase Vmax
Transport of molecules from high to low concentrations with the help of transport proteins
Carrier mediated diffusion
Exit of glucose to the bloodstream
GLUT2 facilitated diffusion
Gibbs free energy except
A. Independent of the mechanism of reaction
B. Provide information only about the direction and equilibrium state of the reaction
C. Provides no information regarding the rate of reaction
D. Provide information only about the direction, equilibrium and rate of reaction
D. Provide information only about the direction, equilibrium and rate of reaction
Enzyme on rate of reaction
Decreases activation energy
Polyssacharide digestion
Hydrolysis of alpha (1,4) glycosydic bond
Secondary active transport
Movement of one molecule down the concentration gradient to power movement of another from low to high
2 factors
Km and Vmax
Bile
Emulsify lipid
Provides measurement for enzyme affinity to substrate
Km
Anything that increases the frequency or energy of collision of substrates
Kinetic
What determines how far the reaction goes
Magnitude
Segregation of metabolic pathways ensuring metabolic efficiency
Compartmentation
Salivary amylase
Hydrolyse amylose
Where start ang protein digestion
Stomach
Why mag stop ang digestion ng carbohydrates sa stomach
Due to secretion of parietal cells
Digestion in the stomach
Peristaltic mixing and churning are examples of mechanical digestion
Function of chylomicrons
For lipid transport directly out of the cell to lacteal
What happens when acid from the stomach enters the duodenum
Secretin is released
The byproduct of lipid digestion by lipase
Diacylglycerol and free fatty acid
Enzyme responsible of digestion of carbohydrates
Amylase
Effect of pH on enzyme
Ionization
Diffusion of water
Osmosis
Transfer groups between atoms with a molecule
Mutases
Absorption of alcohol
Passive diffusion
Not part of catalytic triad
Asparagine
Absorption of iron
Duodenum
Not a role of saliva
Denaturation
Molecule to product and backward to substrate
Equilibrium
Where does protein digestion starts?
Stomach
What will happen when acid from the stomach enters duodenum?
Release of pepsinogen
True of G except:
A. Independent of the mechanisms of reaction
B. Provide info only about the direction and equilibrium state of the reaction
C. Provides no information regarding the rate of reaction
D. Provide information only about the direction, equilibrium and state of reaction
D. Provide information only about the direction, equilibrium and state of reaction
*** NOMENCLATURE
Heme Oxygenase
Oxygenase
How are the polysaccharides digested?
A. Hydrolysis of a1,4 glycosidic bonds
B. Hydrolysis of a1,6 glycosidic bonds
C. Hydrolysis of b1,4 glycosidic bonds
D. Hydrolysis of b1,6 glycosidic bonds
A. Hydrolysis of a1,4 glycosidic bonds
Composition of lactose
1 Glucose + 1 Galactose
Which of the following is true regarding digestion in the stomach?
A. Carbohydrate digestion continues in the stomach
B. No absorption of any compounds occur in the gastric mucosa
C. Peristaltic mixing and churning are forms of mechanical digestion
D. The high gastric pH is needed for protein and lipid digestion
C. Peristaltic mixing and churning are forms of mechanical digestion
How far the reaction will go?
A. Magnitude of the energy
B. Quantity of free energy
C. Strength of energy
A. Magnitude of the energy
Diacylglycerols digested into monoacylglycerols and FFA by hydrolysis of
SN1 and SN3 ester bonds
True about competitive inhibition except:
Binds to the site other than the catalytic site
Digestion of carbohydrates
Amylase
All are true of irreversible inhibitors except
They form dissociable dynamic complex with enzyme
Lipid hydrolysis products
DAG and FFA
Secondary active transport
Higher to lower to power movement of another lower to higher
Negative free energy
Left to right
Low Km
Low concentration of the substrate needs to half saturate the enzyme
Action of salivary amylase
A. Hydrolyzes amylose
B. Hydrolyzes amylopectin
C. Esterifies a1,4 of starch and glycogen
D. Digest b1,4 of cellulose
A. Hydrolyzes amylose
Exit of nutrients from the cell
GLUT2
Hydrolyze at the end of the a.a.
A. Peptidase
B. Elastase
C. Trypsin
D. Carboxypeptidase
D. Carboxypeptidase
When acidic contents of the stomach enters the duodenum
A. CCK is secreted in the Si
B. Pancreatic enzymes are secreted in the SI
C. Bicarbonate is secreted into the SI
D. Secretin is secreted into the SI
D. Secretin is secreted into the SI
Michaelis menten theory
When [S] exceeds [E], when all enzymes are bound, there is an excess of substrates
Substrate concentration is high
0 order
Which of the following is true about pepsin
A. Secreted by parietal cells
B. Secreted as proenzymes
C. Denatures proteins prior to digestion
D. Works in a basic environment
B. Secreted as proenzymes
Energy required to bring all molecule to the transition state
Free energy of activation
Affinity of the enzyme to the substrate
Km
Difference of enzyme and inorganic catalyst
Not altered
Distinct enzyme forms that catalyze the same reaction and arise through gene duplication
A. Lysozymes
B. Reside
C. Homologous
D. Isozyme
D. Isozyme
Inferred from the presence of specific amino acids in the same position in each family member
Conserved residues
2 factors in dealing enzymes
Km and Vmax
Which is true for iron absorption
Absorption is regulated in order to reduce the generation of free radicals
Sigmoid graph
Cooperative binding
Effect of noncompetitive inhibition except:
Increase Vmax
Transport of molecules from high to low concentration with the help of transport proteins
Carrier mediated diffusion
Enzyme on rate of reaction
Decrease activation energy
Proportionality is changing
Mixed order
Primary response, does not cross placenta?
IgM
Secondary response, can cross placenta?
IgG
Found in secretions
IgA
Allergic reactions
IgE
B Lymphocyte
IgD
Half-life of Hb-Hp complex
90 mins
Enzyme in milk that protect against E.coli and bacteria
Milk lysozyme
Rich in antibody
Colostrum
% of water in breastmilk
87%
Storage of human milk except
A. 25C to 27C for 4 hrs
B. 15C to 25C for 8 hrs
C. Ref na 2 doors
D. Deep freeze for 9 mos
D. Deep freeze for 9 mos
Exhibit polymorphism except
Ferritin
Enhances Ca absorption
Lactose
Physiologic jaundice except
Most common cause of conjugated hyperbilirubinemia
Which of the ff is true
The iron of the unoxygenated myoglobin lies outside the plane of the heme ring
Conjugation of bile is catalyzed by
UDP-glucoronyl transferase
Has large capacity that even under the pathologic conditions, transport does not appear to be rate limiting for metabolism of bilirubiin
Facilitated transport system
Reciprocal coupling of proton and O2 binding
Bohr effect
5th coordinating carbon of myoglobin is linked to
Proximal His F8
Fetal Hb
A2y2
Condition where alpha and beta globin chains are absent and decrease in number
Thalassemia
Largest repository of heme
RBC
Sign of good attachment except
A. More areola visible above baby's mouth B. Baby's mouth wide open C. Lower lip turned outwards D. Chin close to the breast E. Baby's position should lie flat
E. Baby’s position should lie flat
Thick milk antibodies
Colostrum
Breast milk affect milk production
A. True
B. False
C. Neither
D. True with increased fluid
B. False
The transfer of iron across the apical membrane of the enterocyte is accomplished via
A. DMT1
B. TfR1
C. TFr2
A. DMT1
Ferric is reduced to the ferrous form by a
A. Ferrireductase
B. Ferrioxidase
A. Ferrireductase
Bilirubin found in bile ductules
A. Bilirubin monoglucoronides
B. Bilirubin diglucoronides
C. UDP-glucoronic acid
B. Bilirubin diglucoronides
Genetic defect of this protein can lead to emphysema
A. A2-macroglobulins
B. A1-antitrypsin
B. A1-antitrypsin
WHO advises breastmilk feeding except
A. After an hour of giving birth
B. Within an hour after giving birth
C. Up to 2 years of age
D. During the 1st 6 months
A. After an hour of giving birth
Minerals found in the mature milk
Na, K, Ca, Fe, Zn, O
Has ferroxidase activity
Haphaestin
Binds to extracorpuscular Hb
Haptoglobin
All of the following are true of O2 dissociation curve of myoglobin except:
During strenuous exercise, release O2 when PO2 of muscles decrease to 20 mmHg (should be 5 mmHg)
Tyrosine to his F8
Hgb M
True of heme except
One ferrous ion is attached to the center of a linear tetrapyrrole (should be cyclic tetrapyrrole)
Hemoglobin
A carrier of both O2 and CO2
Why is it that carbon monoxide does not completely displace O2 from the heme iron
The apoproteins of myoglobin and hemoglobin provide a hindered environment
The reciprocal binding of proton and oxygen
Bohr effect
Which of the following statements is true?
In unoxygenated myoglobin, the iron lies outside the plane of heme ring
Methemoglobinemia
Iron in ferric rather than ferrous
A low PO2 in peripheral tissues promote the synthesis of
2,3 BPG
True of P50 except:
PO2 that half saturates a myoglobin (should be hemoglobin)
True of porphyrin except:
Forms complexes with metal ions bound to carbon atom of the pyrolle ring (nitrogen dapat)
The iron-free porphyrin portion of heme is degraded mainly in the
Liver
Fifth coordination position of the iron is linked to a ring nitrogen of proximal histidine
His F8
Has large capacity that even under pathologic condition, the transport does not appear to be rate limiting for metabolism of bilirubin
Facilitated transport system
Compound excreted in feces
Stercobilin
The bilirubin found in the bile ductules
Bilirubin diglucoronide
Conjugation of bilirubin
UDP glucoronyl transferase
Feme oxygenase is found at
Endoplasmic reticulum
After album-bilirubin complex dissociates, Albumin:
Remains in the plasma
Colorless substance in bilirubin metabolism
Urobilinogen
Cutaneous porphyria, except:
Acute intermittent porphyria
Porphyrin is
Hydrophobic
Carbon monoxide is the direct measure of
Heme oxygenase
Important for secondary response; fixes complement, enhancing bacterial killing
IgG
Physiological jaundice, except:
Conjugated bilirubin (unconjugated dapat)
Hormone secreted from anterior pituitary gland for production of breast milk
Prolactin
Stimulates milk production
Prolactin
A thick milky substance rich in antibodies
Colostrum
Does the size of the breast affect milk production?
No
Signs of good positioning of breastfeeding, except:
Baby’s body is flat against the mother (dili ko sure sa sentence basta dili dapat flat)
Two major proteins in breast milk
60% whey 40% casein
Percentage of water in human milk
87%
WHO recommends that… except:
Breastfeeding should be initiated after 1 hour after birth
Average composition of breastmilk in humans
Water 87%
Lactose 7.2%
Fat 4%
Protein 1%
Principal sugar in human milk which enhances calcium absorption
Lactose
Minerals in mature human milk
Na, K, P, Ca, Fe, Zn
Enzyme in human milk that protects the infant against E. Coli & Salmonella
Milk lysozyme
Human milk protein with bacteriostatic properties, required for iron transport and absorption
Lactoferrin
Most abundant immunoglobulin in human milk secretions
IgA
Which of the following are the guidelines of milk storage, except:
Deep freezer 9 mos.
Concentration of total protein in human plasma
7-7.5 g/dL
Osmotic pressure of arterioles
40 mmHg
In protoporphyria, what enzyme is defective
Ferrochelatase
What plasma glycoprotein is involved in binding extracorpuscular Hgb:
Haptoglobin
What is an important element in the human body because it is found in many of the hemoproteins?
Iron
Enzyme that catalyzes ferric to ferrous
Ferrireductase
