Description : In the skeletal muscle: a. myosin is found in the thick filament b. the thin filament contains actin and troponin c. during stimulus excitation calcium ions are derived from the serum d. tropomyosin masks the myosin-combining sites on the actin
Last Answer : tropomyosin masks the myosin-combining sites on the actin
Description : With reference to the skeletal muscle myofilaments a. actin is the major constituent of thin filaments b. myosin and tropomyosin combine to form the thick filaments c. troponin is a constituents of thin filaments d. tropomyosin prevents the interaction of actin and myosin in the resting state
Last Answer : actin is the major constituent of thin filaments
Description : The contractile proteins in a muscle are (1) Actin and Myosin (2) Actin and Tropomyosin (3) Myosin and Troponin (4)Troponin and Tropomyosin
Last Answer : (1) Actin and Myosin Explanation: Muscle fibers or myofibrils are formed of three types of proteins which are (1) contractile, (2) regulatory, and (3) structural. Contractile proteins are the force ... are Actin which is part of thin filament and Myosin, which is part of the thick filament.
Description : The contractile proteins in a muscle are (1) Actin and Myosin (2) Actin and Tropomyosin (3) Myosin and Troponin (4) Troponin and Tropomyosin
Last Answer : Actin and Myosin
Description : Calcium is important in skeletal muscle contraction because it (a) binds to troponin to remove the masking of active sites on actin for myosin (b) activates the myosin ATPase by binding to it ... filament (d) prevents the formation of bonds between the myosin cross bridges and the actin filament.
Last Answer : (a) binds to troponin to remove the masking of active sites on actin for myosin
Description : Calcium is important in skeletal muscle contraction because it :- (1) binds to troponin to remove the masking of active sites on actin for myosin. (2) activates the myosin ATPase by binding to ... filament. (4) prevents the formation of bonds between the myosin cross bridges and the actin filament.
Last Answer : (1) binds to troponin to remove the masking of active sites on actin for myosin.
Description : The contractile protein of skeletal muscle involving ATPase activity is (a) troponin (b) tropomyosin (c) myosin (d) α-actinin.
Last Answer : (c) myosin
Description : The phase of contraction of a muscle occurs when: a) tropomyosin binds and releases actin b) myosin binds and releases actin c) actin binds and releases myosin d) none of the above
Last Answer : ANSWER: B -- MYOSIN BINDS AND RELEASES ACTIN
Description : Which one of the following is the correct matching of three items and their grouping category? Items Group (a) Ilium, ischium, Coxal bones of pelvic girdle pubis (b) Actin, myosin, Muscle proteins rhodopsin (c) Cytosine, uracil, Pyrimidines thiamine (d) Malleus, incus, Ear ossicles cochlea
Last Answer : (a) Ilium, ischium, Coxal bones of pelvic girdle pubis
Description : Which of the following is the contractile protein of a muscle? (a) Tropomyosin (b) Tubulin (c) Myosin (d) All of these
Last Answer : (c) Myosin
Description : Which one of the following pairs of chemical substances, is correctly categorised? (a) Calcitonin and thymosin - Thyroid hormones (b) Pepsin and prolactin - Two digestive enzymes secreted in ... and myosin - Complex proteins in striated muscles (d) Secretin and rhodopsin - Polypeptide hormones
Last Answer : (c) Troponin and myosin - Complex proteins in striated muscles
Description : The functional unit of contractile system in striated muscle is (a) sarcomere (b) Z-band (c) cross bridges (d) myofibril.
Last Answer : (a) sarcomere
Description : The myofilaments of muscles consist primarily of two proteins. These two proteins are called: a) actin and myosin b) progesterone and testosterone c) progesterone and estrogen
Last Answer : ANSWER: A -- ACTIN AND MYOSIN
Description : The H-disk in the skeletal muscle fibre is due to (a) the absence of myofibrils in the central portion of Aband (b) the central gap between myosin filaments in the Aband Questions (c) the ... myosin filaments in the A-band (d) birefringence of myosin filaments in the central portion of A-band
Last Answer : Ans:(c)
Description : The major fibrous proteins are: a) peptone and edestin b) glutelin and leucine c) valine and lysine d) myosin and actin
Last Answer : ANSWER: D -- Myosin and Actin
Description : The organic portion of bone consists of which one of the following proteins. a) fibrin b) collagen c) actin d) myosin
Last Answer : ANSWER: B -- COLLAGEN
Description : The following are true about the smooth muscle cells: a. presence of a striated appearance b. do not contain actin and myosin c. spontaneous muscle contraction d. mitochondria are absent
Last Answer : spontaneous muscle contraction
Description : The H-zone in the skeletal muscle fibre is due to (a) the central gap between actin filaments extending through myosin filaments in the A-band (b) extension of myosin filaments in the central portion ... the central portion of A-band (d) the central gap between myosin filaments in the A-band.
Last Answer : (a) the central gap between actin filaments extending through myosin filaments in the A-band
Description : Assertion : `Ca^(2+)` plays important role in the musclc contraction. Reason : `Ca^(2+)` Combines with troponin chain, displacing tropomyosin allowing
Last Answer : Assertion : `Ca^(2+)` plays important role in the musclc contraction. Reason : `Ca^(2+)` ... false . D. If both Assertion and Reason are false.
Description : What is the function of troponin and tropomyosin and what negates them?
Last Answer : Need answer
Description : Consider the following statements: 1. Cross bridges can cause muscle contraction. 2. They are able to oscillate back and forth and hook up with active sites on actin filaments 3. The bridges enable the thin filaments to pull the thick filaments by a ... (a) 1, 2 (b) 2, 3 (c) 1, 2, 4 (d) 1, 2, 3, 4
Description : The number of thick myofilaments (myosin) surrounding Single thin myofilament (actin) are
Last Answer : The number of thick myofilaments (myosin) surrounding Single thin myofilament (actin) are A. 3 B. 6 C. 2 D. 4
Description : A protein having both structural and enzymatic traits is (A) Myosin (B) Collagen (C) Trypsin (D) Actin
Last Answer : Answer : A
Description : The protein present in the finger nail is (1) Actin (2) Myosin (3) Globin (4) Keratin
Last Answer : (4) Keratin Explanation: Keratin is a fibrous protein making up most cells found in our nails and hair and the epidermis layer of our skin. It also makes up fish scales and crustacean shells, bird feathers and beaks, and animal horns and hooves.
Description : Sliding filament theory can be best explained as (a) actin and myosin filaments do not shorten but rather slide pass each other (b) when myofilaments slide pass each other, myosin filaments shorten ... filaments do not shorten (d) actin and myosin filaments shorten and slide pass each other.
Last Answer : (a) actin and myosin filaments do not shorten but rather slide pass each other
Description : Mitotic spindle is mainly composed of which protein? (a) Actin (b) Myosin (c) Actomyosin (d) Myoglobin
Last Answer : c) Actomyosin
Description : Microtubules consist of helically stacked molecules of the protein (A) Actin (B) Myosin (C) Keratin (D) Tubulin
Last Answer : (D) Tubulin
Last Answer : Keratin
Description : The ion that must be present in adequate amount for the binding of cross bridges with actin is
Last Answer : The ion that must be present in adequate amount for the binding of cross bridges with actin is A. `Ca^(2+)` B. `Na^(+)` C. `K^(+)` D. `Mg^(2+)`
Description : Name the two important proteins due to which striated appearance is seen in myofibril
Last Answer : Name the two important proteins due to which striated appearance is seen in myofibril
Description : The segment of a myofibril that is called a sarcomere runs from (a) one Z-line to the next Z-line (b) one A-band to the next A-band (c) one H-zone to the next H-zone (d) one end of a skeletal muscle to the opposite end
Last Answer : Ans:(a)
Description : The contractile unit of muscle is a part of myofibril be- tween
Last Answer : The contractile unit of muscle is a part of myofibril be- tween A. Z line and I band B. Z line and Z line C. Z line and A band D. A band and I band
Description : Stimulation of a muscle fibre by a motor neuron occurs at (a) the neuro-muscular junction (b) the transverse tubules (c) the myofibril (d) the sacroplasmic reticulum.
Last Answer : (a) the neuro-muscular junction
Description : Recrudescences attending 3 day artesunate therapy of chloroquine resistant falciparum malaria can be prevented by combining it with a single dose of: A. Quinine B. Primaquine C. Tetracycline D. Mefloquine
Last Answer : D. Mefloquine
Description : The sequence of events in muscle contraction a. action potential depolarise the T-tubules b. depolarisation of T-tubules release calcium from sarcoplasmic reticulum c. calcium binds to the troponin-tropomycin complex d. all above
Last Answer : all above
Description : Regulator gene controls chemical synthesis (Operon concept) by (a) Inhibiting transcription of mRNA (b) Inhibiting enzymes (c) Inhibiting passage of mRNA (d) Inhibiting substrate enzyme reaction
Last Answer : Ans. ((a))
Description : Corrosion in Steel girder bridges may be prevented by : a) Protective coatings by painting b) Metallising c) Use of epoxy based paints d) All the above*
Last Answer : d) All the above*
Description : Myosin is one of two proteins that make up the myofibrils of striated muscles. Name the other protein.
Last Answer : ANSWER: Actin
Description : Name the ion responsible for unmasking of active sites for myosin for cross-bridge activity during muscle contraction. (a) Calcium (b) Magnesium (c) Sodium (d) Potassium
Last Answer : (a) Calcium
Description : In biological studies which of the following is used to refer to the oxygen-binding, iron-containing, conjugated protein complex present in the sarcoplasm of muscle cells? a) myelin b) myosin c) myoglobin d) none of these
Last Answer : ANSWER: C -- MYOGLOBIN
Description : $ Rhodopsin of rod cells and iodospin of cone cells of retina are proteins ! Myosine and Actin are contractile proteins
Last Answer : $ Rhodopsin of rod cells and iodospin of cone cells of retina are proteins ! Myosine and Actin are ... wrong D. If both As and R are wrong.
Description : What is the function of proteins like microtubules and actin filaments?
Last Answer : Give structure to cells.
Description : During muscle contraction in humans, the (a) sarcomere does not shorten (b) A band remains same (c) A, H and I bands shorten (d) actin filaments shorten.
Last Answer : (b) A band remains same
Description : Dantrolene sodium reduces skeletal muscle tone by: A. Reducing acetylcholine release from motor nerve endings B. Suppressing spinal polysynaptic reflexes C. Inhibiting the generation of muscle action potential D. Reducing Ca2+ release from sarcoplasmic reticulum in the muscle fibre
Last Answer : D. Reducing Ca2+ release from sarcoplasmic reticulum in the muscle fibre
Description : The potential difference across the membrane of a relaxed muscle fiber is called resting potential. It amounts to about
Last Answer : The potential difference across the membrane of a relaxed muscle fiber is called resting potential. It amounts to ... C. `100m V` D. `50- 100mV`
Description : In the normal resting state of humans, most of the blood glucose burned as fuel is consumed by (A) Liver (B) Adipose tissue (C) Muscle (D) Brain
Description : Compared to the resting state, vigorously contracting muscle shows (A) An increased conversion of pyruvate to lactate (B) Decreased oxidation of pyruvate of CO2 and water (C) A decreased NADH/NAD+ ratio (D) Decreased concentration of AMP CARBOHYDRATES AND CARBOHYDRATE METABOLISM 21
Last Answer : A
Description : The sodium/potassium pump is primarily responsible for the: a) resting potential b) action potential c) excretion of salts d) contraction of muscle fibers
Last Answer : ANSWER: A -- RESTING POTENTIAL
Description : The distance or length of the myofibril between two adjacent z-bands is called
Last Answer : The distance or length of the myofibril between two adjacent z-bands is called