Animal cells each have a centrosome and lysosomes, whereas plant cells do not. Plant cells have a cell wall, chloroplasts and other specialized plastids, and a large central vacuole, whereas animal cells do not.
Well-sorted sediments have grains of similar size, and are the result of much sediment transport and earth processes which segregated the sediment by depositing different size fractions in different places.
Answer:
The condition of the Earth had to become favourable before it could support any form of life.
The formation of the different layers around the earth like the ozone layer was necessary before life could originate. Primitive species such as some prokaryotes were able to live in hydrothermal conditions during the initial times. With the passage of time, as the concentration of oxygen increased due to photosynthetic prokaryotes, situations became favourable for eukaryotic organisms to arise.
Activation of pepsinogen starts when hydrocholoric acid (HCl), which is secreted by the parietal cells partially activates pepsinogen (pepsinogen* in figure). This partially active enzyme then cleaves the peptide from other pepsinogen molecules to form active pepsin.
Answer:
Explanation:
When enzyme does not work properly it is said to be inactive and this affect its efficiency.
Substrate concentration - Enzyme requires adequate substrate concentration to be effective, when the concentration is high the enzyme activity increases and when it is low it decreases.
Temperature - Enzymes are more active at specific temperature at very high temperature enzyme can be denatured leading to a loss of its activity. Hence, enzyme should be made to work at its optimum.
pH- Enzymes are active at specific pH, when the pH is altered enzymatic activity may be reduced or enzyme become inactive. Hence, pH of enzymes should be maitained.