1. a. The thick filament is composed of what molecule MYOSIN b. Flexing the head of this molecule provides what is known as the POWER STROKE. 2. The myosin head contains binding sites for what two molecules a. ATP b. ACTIN 3. Three molecules make up the thin filament. a. Which molecule has a binding site for myosin heads ACTIN b. Which molecule covers this binding site TROPOMYOSIN c. Which molecule has a binding site for calcium ions TROPONIN 4. What molecule must bind to the myosin head in order for it to disconnect with Actin ATP 5. Hydrolysis of the molecule in question 4 returns the myosin molecule to the HIGH ENERGY confirmation. 6. Binding of the myosin heads sequentially prevents CROSS BRIDGE BINDING of the thin filament. (PULLING THEM TOWARD THE CENTER OF THE SARCOMERE BUT THEN ACTIN (ON THIN FILAMENTS) RELEASES THE ADP AND P SO THAT MYOSIN HEAD IS RELEASED AND CAN BIND AGAIN) 7. Name three roles for ATP in the contraction of muscle. a. PROVIDE THE ENERGY FOR THE POWER STROKE (MYOSIN HEAD BENDS) b. DISCONNECTING THE MYOSIN HEAD FROM ACTIN c. ACTIVELY TRANSPORTING CA OUT TO THE SARCOPLASMIC RETICULUM 8. What molecule is connected to the Z line THIN FILAMENTS 9. Which of the following shorten during contraction (may be more than one) a. Thin filament DOES NOT b. Sarcomere SHORTENS c. H zone SHORTENS d. Thick filament DOES NOT 10. What is the name of the condition in which muscles become rigid after death RIGOR MORTIS b. What is this condition due…
Sliding Filament Theory and Muscle Tissues study guide
Binding of the myosin head sequentailly prevents "_____________" of the thin filament. This makes it seem that the myosin is "_______" the actin ______.
Calcium ions are moved back into the SR by the process known as ____________ which is facilitated by specialized _________________. This process requires___.
Calcium Ion Pumps
During muscle contraction…
T-tubules: - part of sarcolemma—carries action potential
Triad: - T-tubule + 2 terminal cisternae
7. Myofibrils consist of contractile proteins called SARCOMERES
Name the two types and what they’re composed of:
THICK FILAMENTS composed of MYOSIN
THIN FILAMENTS composed of ACTIN
8. Arrangement of myofilaments. Give the letter name of each band:
Dark band A band
Light band I band
Match two definitions with each band:
I BAND- contains only thin filaments
I BAND- contains both thick…
releases phosphate molecule
Growth/shrinkage of actin filaments is controlled by various other proteins
Monomer sequestering proteins
Cross linking proteins (cell cortex)
What’s the difference between microfilament and microtubules (tube shape)?
Location? Base molecules?
Of myosin family, myosin I and II are main family
ATP binding proteins
Analogous to how dynein works in microtubules
Myosin II is mostly muscle specific
Myosin motor protein…
Synthesis of ATP
During aerobic respiration, 38 ATP molecules have the potential to be produced when Glycolysis, the Link Reaction, the Krebs cycle and the Electron Transport Chain occur. Glucose is phosphorylated as two ATP molecules donate their Pi to it. This phosphorylated glucose is then split into two Triose Phosphates which is then changed into 2 pyruvate molecules as two lots of NAD are reduced into NADH and four molecules of ATP are released. The pyruvates then go on to form AcetylcoenzymeA…
contractile proteins called _____ Myofilaments ______________. Name the two types and what theyre composed of ____ thin filament ___________ composed of ______ The protein Actin _____________ _______ thick filament ________ composed of _____ The protein myosin. ______________ 8. Arrangement of myofilaments. Give the letter name of each band Dark band ( _ A __ band Light band ( _ I __ band Match two definitions with each band The I band - contains only thin filaments The A band - contains both thick…
Thanks, Carl Johnson
Types of Muscles in Vertebrates
All three types of muscle use actin and myosin, but they are controlled and organized differently
Smooth muscle cells are the simplest muscle cells: single nucleus per cell spindle-shaped often in smooth sheets not "striated" because the actin and myosin are not arranged regularly within the cell as is true for cardiac and skeletal muscle cells Smooth muscle: moves food through…
The Importance Of ATP
Adenosine triophosphate (ATP) is an activated nucleotide found in all living cells that acts as an energy carrier. An ATP molecule is made up of three components: a ribose sugar molecule, a nitrogenous base (adenine) and three phosphates. At the centre of the molecule is the ribose sugar, which is then attached to adenine on one side and a chain of three phosphates on the other side. These phosphates are the key to the activity of ATP. It's role is to store and then release…
muscle cell and contain myosin and actin
Myofilament – Actin and myosin
Myosin filaments– Thick filaments
Actin filaments – Thin filaments
Cross-bridge – Heads of myosin molecules that bind with actin
Sarcomere – Smallest contractile unit of a skeletal muscle formed by myosin and actin filaments (from z-line to z-line)
M-bridge – Where other myosin filaments are anchored to in the middle of the sarcomere
Z-Line – At each end of the sarcomere where actin is anchored
Myosin is surrounded by 6 actin…
-Sebacious gland (oil) secretion
-hold cells together and form a permeability barrier
-small, specialized contact region between cells containing protein channels
-communication by allowing ions and small molecules to pass from one cell to another
-weak binding of cells to one another found in epithelial cells that are subjected to stress.
-connect epithelial cells to the basement membrane
1. CONNECTIVE TISSUE…
numbers of muscle fibres per motor unit.
J S Lauritzen
Structural components of a skeletal muscle
Elementary motor of skeletal muscle.
Bounded by Z lines (disks).
Mainly contains contractile proteins: actin, myosin and tropomyosin-troponin.
Also contains myoglobin (for O2 storage and transport).
• Chains of sarcomeres lined up end to end.
• Many bundled in parallel within muscle cell.
• Bundle of myofibrils lying in parallel.