Answer:
The plant cell wall is strengthened by the molecular structure of cellulose. Cellulose is made up of ß-glucose arranged upside down, this arrangement aided hydrogen bonds between the hydrogen ions of the hydroxyl group and oxygen of the of the ring of same betta -glucose.
The aggregation of the hydrogen bonds give bundles of strong tensile strength of cellulose called the microfibrils (of 60-70 celluose molecules).They are held together in bundled called fibers.T<u>hese is the source of plant cell walls strength.
</u>
<u />
Collagen is the main extracellur matrix (EM) in animal cells.It is a glycoprotein made up of 25%of body protein of animals.Each collagen molecule is made of helix shaped ,three polypeptide chains, wound around each other to form<u> triple helix.</u>The bonds holding helix together are hydrogen and covalent bonds.
Each triple helix is attached to adjacent collagen molecule, parallel to it. The covalent bonds formed a cross link which held the collagen molecules together forming FIBRILS. This gives flexibility to collagen, while maitaing strong tensile strength. This is what is responsible for the structural strength of cell membrane
.
.The EM,is futher reinforced with carbohydrate molecules(proteoglycans) which<u> aided in water movements by osmosis following sodium movements into the matrix.</u>
Answer:
Vacuum
Explanation:
A vacuum is usually defined as a space in which there is an absence of matter. It can also be said that there is an extremely low amount of pressure due to which the particles present in it are not affected by any type of process that occurs in space. The value of pressure is lower than the value of normal atmospheric pressure.
For example, sound cannot travel in space because there is no medium such as water and air through which the sound waves can propagate.
Answer:
Answered below
Explanation:
On piercing his foot, the pain receptors called nociceptors, found in the skin, are activated. Nociceptors exist at the nerve endings of the primary afferent neurons. Signals travel along the first order neurons which have cell bodies within the dorsal root ganglia of the spinal cord. In the dorsal root ganglia, the signals are taken up at the synapse with the second order neurons which have cell bodies in the nuclei of the cranial nerves within the brainstem. These neurons ascend cranially in the spinothalamic tract to the thalamus. The third order neurons lie within the ventral posterolateral nucleus of the thalamus. They terminate at the somatosensory cortex where the signals are being processed and returned as a sensation of pain.
