Saturday, 9 March 2013

Pore Protein and Carrier Protein

Pore Protein or Channel
When a channel is opened with a conformational switch, it is open to both environment simultaneously (extracellular and intracellular); channels are either in open state or closed state.

Pores are continuously open to these both environment, because they do not undergo conformational changes They are always open.

Carrier Protein

Pathway in a carrier protein is not open smiltaneously to the both environment. Either its inner gate is open, or outer gate is open, or both gates are closed. 

Carrier has binding sites, but porins and channel proteins have not.

When a channel is opened, thousands to millions of ions can pass through the membrane in one time, but only one or a small amount of molecules can pass through a carrier molecule. 

Muscle Dystrophy

mutated gene on the X chromosome usually in boys

Simailarity and difference between Hinge Joint (S) and Ball and Socket (T)

F1 Both Joint S and Joint T has a cavity filled with svnovial fluid // lined with synovial membrane
El Synovial fluid acts as lubricant to reduce friction between bones // absorbs shock of the movement.
F2 The end surfaces of the humerus bone of Joint S and Joint T are covered with cartilage
E2 To protect the bone / reduce friction between the bones
F3 Both Joint S and T are connected with ligaments
E3 to absorb shock // strengthen the articulation of bones/ joint.

D1 Joint S is hinge joint
E4 Joint S allows the movement of bones in one plane / direction
D2 Joint T is ball-and-socket joint.
E5 Joint T allows rotational movement of bones in all directions.

What is osteoporosis

P1 : the bone become thinner / more brittle / porous / fragile.
P2 : Loss of bone mass.
P3 : Lack of calcium / phosphorus / vitamin D

Movement in Human

Pl- Tendons, ligaments, bones, muscles and joints are important features in a movement,
P2- Tendons connect muscles to bones
P3- Tendons are strong and non elastic
P4- Force is transferred to bones through tendons.
P5- Movement at the joint is possible with the aid of ligaments.
P6- Ligaments connect two bones together
P7-to give support and strength to the joint.
P8- Ligaments are strong and elastic.
P9- The quadriceps / extensor muscles contract while the biceps femoris muscles relax and the leg is straightened.
P10- The biceps femoris muscles contract while the quadriceps / extensor muscles relax and the leg is bent.
P11- Calf muscles contract to lift up the heels.
P12-Feet push downward and backward
P13-Repeated contraction and relaxation of muscles result in the running movement.

Types of Joints

Hip Replacement - Due to ostreoporosis

Disadvantages of having a hip replacement.

It may cause the surrounding tissue to become inflamed
Dislocation /blood clot
Risk of infection after surgery
Her legs may not be exactly the same length
The artificial hip will eventually need replacing

Intervertebral disc

Function of Intervertebral Disc

F: permit movement of vertebral column
P: absorb shock / reduce friction

Symptoms of Osteoporosis

Fractures of the vertebrae / wrist / hips

Reduction in height

Stooped posture

Grasshopper Jumping

A grasshopper has antagonistic muscles called the flexor and extensor muscles which ( are attached to the interior of the exoskeleton)

The rear legs are bigger and longer and (are adapted for jumping).

Flexor muscle contract to flex the leg / prepare for jumping.

Flexor muscle relaxed, extensor muscle contracts.

Causes the rear legs to extend and pushes against the ground 

The thrust created propels the grasshopper forwards and upwards.

Movement of Earthworm

Earthworm have a hydrostatic skeleton 1m

The body wall has both longitudinal and circular muscle which
act antagonistically

The contraction of the circular muscle and relaxation of the
longitudinal muscles cause the segment to extend.

Chaetae are extended to grip the soil / ground

The contraction of the longitudinal muscle and relaxation of
the circular muscle cause the segment to shorten.

Contraction and relaxation of these muscles causes the
transfer of hydrostatic pressure from the anterior to the

It causes the body to move to the front. 

The chaetae are retracted to allow movement