Physiology Exam 1

Created by Hope Knowlton

Are cell membranes more permeable to lipid-soluble or water-soluble substances?
Lipid-soluble substances

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TermDefinition
Are cell membranes more permeable to lipid-soluble or water-soluble substances? Lipid-soluble substances
large protein responsible for passive elasticity (two names for it)Titin (also known as connectin)
what is the largest sinle polypeptide?Titin/connectin
Band within sarcomere that is dark and does not move during contractionA band
Band within sarcomere that is light and moves during muscle contraction I band
which parts interdigitate to make a muscle contractactin and myosin
covers active sites and prevents interaction with myosin
Troponin I binds what? Troponin T binds? and Troponin C binds?Actin, tropomyosin, calcium
Which Troponin subunit binds to create a conformational change to allow myosin to bind to actinTroponin-C (calcium binds)
How many binding sites does myosin have and what are theytwo- ATP and actin
How many heads does one myosin molecule havetwo
How many light and heavy chains does myosin havetwo heavy and four light
What does calcium bind to in the muscle celltroponin
Explain the four stages of the "Walk-Along Theory"1. myosin head binds to actin (new ATP comes in and causes) 2. Myosin head to release from actin (ATP hydrolysis which causes) 3. Myosin head to become cocked/active (ADP and Pi) 4. Myosin head attaches to actin and pulls =power stroke (ADP bound)
Explain Rigor Mortis less O2 available after death, so decrease in ATP, no more ATP cant cause conformational change to pull myosin off actin so stuck in rigor state
AT= TT-PT Explain this equation active tension cannot be measured directly. but passive and total tension can. so this equation calculate
T or F: active tension falls away linearly with increasing length (as well as with decreasing length)True
Isotonic vs isometric Isotonic: muscle changes length to contract heavy object Isometric: object to heavy muscle cannot change length when contracts
Define motor unitit is the motor neuron and all of the muscle fibers that it innervates
What type of skeletal muscle: slow, oxidative, red muscle, low glycolytic enzyme content, lots of mitochondria, small diameter, lots of myoglobin Type I
What type of skeletal muscle: glycolytic, fast, larg diameter, white muscle, few mitochondria,