Cellular respiration is a metabolic pathway that breaks down glucose and produces ATP. The stages of cellular respiration include glycolysis, pyruvate oxidation, the citric acid or Krebs cycle, and oxidative phosphorylation.
During cellular respiration, a glucose molecule is gradually broken down into carbon dioxide and water. Along the way, some ATP is produced directly in the reactions that transform glucose. Much more ATP, however, is produced later in a process called oxidative phosphorylation. Oxidative phosphorylation is powered by the movement of electrons through the electron transport chain, a series of proteins embedded in the inner membrane of the mitochondrion.
These electrons come originally from glucose and are shuttled to the electron transport chain when they gain electrons.
As electrons move down the chain, energy is released and used to pump protons out of the matrix, forming a gradient. Protons flow back into the matrix through an enzyme called ATP synthase, making ATP. At the end of the electron transport chain, oxygen accepts electrons and takes up protons to form water. Glycolysis can take place without oxygen in a process called fermentation. The other three stages of cellular respiration—pyruvate oxidation, the citric acid cycle, and oxidative phosphorylation—require oxygen in order to occur. Only oxidative phosphorylation uses oxygen directly, but the other two stages can't run without oxidative phosphorylation.). As electrons move down the chain, energy is released and used to pump protons out of the matrix, forming a gradient. Protons flow back into the matrix through an enzyme called ATP synthase, making ATP. At the end of the electron transport chain, oxygen accepts electrons and takes up protons to form water.
Glycolysis can take place without oxygen in a process called fermentation. The other three stages of cellular respiration—pyruvate oxidation, the citric acid cycle, and oxidative phosphorylation—require oxygen in order to occur. Only oxidative phosphorylation uses oxygen directly, but the other two stages can't run without oxidative phosphorylation.
Answer:
3. the absence of a cell wall in human cells
Explanation:
Animal cells do not have cell walls. Cell membranes separate the cytoplasm of the animal cells from the surroundings and maintain their interior. Plant cells have cellulosic cell walls. A cell wall surrounds the cell membrane of a plant cell. Cell walls serve to provide structural support and protect plant cells from pathogens. Cell walls also help keep excess water out of cells so they do not burst. Therefore, human cheek cells would not have cell walls while the onion cells would have cell walls made up of cellulose.
Kingdom Plantae includes all the plants on the earth. They are multicellular, eukaryotes and consist of a rigid structure that surrounds the cell membrane called the cell wall. Plants also have a green coloured pigment called chlorophyll that is quite important for photosynthesis.
The function of protein that helps chemical react is catalyzing
