Topic 7 ~ Run For Your Life Flashcards
Definition of antagonistic
A pair of muscles that work together as muscles can only pull so 2 are needed to move a bone to and fro
What is an extensor muscle
A muscle that contracts to cause extension of a joint
What is a flexor muscle
A muscle that contracts to reverse the movement of extensor muscles
What is synovial fluid
Fluid found in a cavity within a joint that lubricates the bones enabling them to move freely
What is the function of ligaments in a joint
Joins bone to bone
Strong and flexible
What is the function of the synovial membrane
It secretes synovial fluid
What is the function of the tendon in a joint
Joins the muscle to bone
What is the function of cartilage in a joint
Absorbs synovial fluid
Acts as a shock absorber
What is the function of pads of cartilage
Gives additional protection
What is the function of the fibrous capsule
Encloses the joints
What are muscle fibres and their adaptations
Single muscle cells
Long in length
Each has several nuclei
Why do muscle fibres have several nuclei
A single nucleus could not effectively control the metabolism of such a long cell
What’s the structure of muscle fibres
Bundles of myofibrils that is made up of repeated units of sarcomeres
Structure of sarcomeres
Made up of 2 types of protein
- actin (thin)
- myosin (thick)
What happens to sarcomere when the muscle contracts
The actin moves between the myosin, shortening the length of the sarcomere and therefore the length of the muscle
What is the role of calcium in muscle contraction
- Calcium released from sarcoplasmic reticulum
- diffuses through sarcoplasm
- attaches to troponin causing it and tropomyosin to move, exposing the myosin binding sites
Describe the sliding filament theory
- calcium attaches to troponin causing it and tropomyosin to move, exposing the myosin binding sites
- myosin heads bind forming crossbridge
- ADP and Pi are released
- myosin head nods forward moving the actin towards centre of sarcomere
- ATP binds to myosin head causing it to detach from actin
- ATPase hydrolyses ATP forming ADP and Pi
- myosin head returns to upright position
What is BMR (basal metabolic rate)
Measure of the minimum energy requirement of the body at rest to fuel basic metabolic processes
How is BMR measured
By recording oxygen consumption
- no food consumed for 12 hours
- body totally at rest
- in a thermostatically controlled room
Why is glucose and oxygen not brought together directly and instead split in several steps
Because it would release very large amounts of energy quickly which would damage the cell
Describe the process of glycolysis
- glycogen is hydrolysed to glucose 6C
- 2Pi is added to glucose from 2 ATP molecules
- glucose is split into 2x phosphorylated 3C compounds
- each intermediate is oxidised to 3C pyruvate
- 2 hydrogen atoms are removed and reduce NAD
- 4ATP is formed as 2Pi from intermediate is transferred to 4ADP and 2Pi
What is substrate-level phosphorylation
When energy for the formation of ATP comes from the substrates
(ATP directly made)
