When SA Node triggers Atria goes into Systole !! and when the signal reaches to AV node and from there it goes to Bundle of His making Ventricle to systole or constrict !!
So your answer is Systole !!
2: carbon can be found in the atmosphere, rocks, soil, & fossil fuels,
Answer:
the pH
Explanation:
The condition that should not be kept the same in each of the five test tubes is the pH.
Since <u>the aim of the experiment is to investigate the effect of pH on the activity of the lipase enzyme</u>, the pH is, therefore, the <em>independent variable</em>. Thus, it must be controlled or varied in all the test tubes in order to see its effect on the activity of the enzyme, which, in this case, would be the dependent variable.
The right answer is the burning of fossil fuels.
While all these proposals have a bad impact on the biosphere, Proposal B is the only one that has a direct link to climate change.
Air pollution by combustion is an alteration of air quality that can be characterized by measurements of chemical, biological or physical pollutants present in the air, with consequences that are detrimental to human health, to living beings , climate, or material goods.
Answer:
The correct answers are option A. "tethering proteins to the cell cortex", B. "using barriers such as tight junctions", C. "tethering proteins to the extracellular matrix", D. "forming a covalent linkage with membrane lipids", E. "tethering proteins to the surface of another cell"
Explanation:
According to the fluid-mosaic model, the components of cell membranes are in constant movement forming a barrier to avoid unwanted exterior component internalization and to avoid the loss of precious internal components. This constant movement could cause that proteins move across the plasma membrane. But, this is avoided by several mechanisms including:
A. Tethering proteins to the cell cortex. The cell cortex is a rigid structure made of actin and actomyosin. Proteins found in the plasma membrane are tethered to this structure to restrict their movement.
B. Using barriers such as tight junctions. Tight junctions are barriers found in epithelia made of claudin and occludin proteins. These barriers are impenetrable, which avoid the movement of proteins in the cell membrane.
C. Tethering proteins to the extracellular matrix. The extracellular matrix is made of several proteins and macromolecules that provide a structural and biochemical support to cells that are nearby. Proteins could be tethered to this rigid structure as well.
D. Forming a covalent linkage with membrane lipids. The proteins in the cell membrane that form a covalent linkage with membrane lipids are known as lipid-anchored proteins, or lipid-linked proteins.
E. Tethering proteins to the surface of another cell. When cell-cell communication take place it is possible that proteins in the cell membrane got tethered to the surface of the other cell.
