<h2>Membrane potential </h2>
Explanation:
- Membrane potential represents charge difference across the membrane, all biological cells are negative inside (cytoplasm) and positive outside (due to difference in ionic distribution)
- In a typical neuron cell membrane potential of cytoplasm is negative at rest (when no stimulus is applied) hence called resting membrane potential
- Resting membrane potential of excitable cells is established by Na+ and K+pump
- Repolarization starts with the efflux of K+ by the opening of voltage gated K+ channels
- Voltage gated K+ channels starts to open when voltage gated Na+ channels becomes inactive
- Hyperpolarization occurs due to excessive efflux of K+ by voltage gated K+ channels
- Additional efflux of K+ occurs due to slow inactivation of voltage gated K+ channels
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:
A. aneuploidy; trisomic
Explanation:
Aneuploidy means having more numbers of chromosomes than usual while polyploidy means having an abnormal number of chromosome sets. Down syndrome is a trisomy on chromosome 21 meaning there are 3 chromosomes for chromosome set 21.
Answer:
Fine focus.
Explanation:
If you're referencing a microscope, then it would be fine focus. Coarse focus is a basic focus used to properly see a specimen, while fine focus enhance clarity and precision. To use both, you have to gently twist a knob until you can see the specimen at a desired clarity.
Here's a reference image if you need it, it's labeled all the parts of a microscope.
