Exam Flashcards
Name the muscle structures from biggest to smallest
Epimysium, muscle fibre, perimysium, fascicles, endomysium, myocyte, sarcoplasmic reticulum, myofibril, sarcomere, myofilament
4 Functions of skeletal muscle
Produce tension, produce body movement, mobilise/stabilise bones, maintain posture
Prime mover (agonist pairs)
Muscles that make the major contribution to a movement due to their contraction
Antagonist muscle (agonist pairs)
Muscles opposing the prime mover. Relax and lengthen to allow the agonist to move
4 classifications of muscles
Flexors, extensors, abductor, adductor
Sliding filament theory
1) nerve impulse is sent through axon to the neuromuscular junction
2) acetylcholine carries the nerve impulse and binds to muscle receptors
3) t-tubules spread signals to myofibrils which triggers calcium production
4) calcium binds to troponin, causing tropimyosin to expose binding sites on actin strand
5) ATP from mitochondria brings myosin heads in contact with actin binding sites
6) energy from broken down ATP causes myosin heads to change shape and the filaments move, shortening the sarcomeres
7) previous ATP leaves and a new ATP molecule binds to myosin head, giving it energy to move back to its original position
What are 3 requirements for muscle contraction
ATP, calcium ions, nerve impulse
What is the purpose of mitosis
Cell division for growth, repair and asexual reproduction
What are the stages of mitosis
Interphase Prophase Metaphase Anaphase Telophase Cytokinesis
What’s the purpose of meiosis
To produce gametes with a haploid number of chromosomes, ready for fertilisation
How does variation occur in meiosis
1) crossing over
2) random alignment
3) independent assortment
Explain the process of DNA replication
1) DNA helicase splits the DNA strands into sense and anti sense strands
2) Primase makes DNA primer
3) DNA polymerase binds to primer (works 5” - 3”) and adds nitrogen bases
4) leading & lagging strand (Okazaki fragments)
5) Exonuclease removes all primers from strands
6) DNA polymerase fills in gaps between fragments
7) DNA ligase seals fragments, forming a continuous strand
