Answer:
Anticodon
An anticodon is a trinucleotide sequence complementary to that of a corresponding codon in a messenger RNA (mRNA) sequence. An anticodon is found at one end of a transfer RNA (tRNA) molecule.
Explanation:
Arthritis is a term that is initially used to describe inflammation of the joints. Cartilage is a type of body tissue that keeps joints moving freely and functional well, and when they begin to break down or get inflamed, the joints don’t work as well, and it becomes painful to move
Answer:
A. a developing nation
Explanation:
Age pyramids are the age structure diagrams that represent the number and proportion of people at each age in a population. The base of the age pyramids represents the population in pre-reproductive age which is from 0 to 10 years. The overall shape of an age pyramid indicates if the population is increasing, stationary, or shrinking.
The age structure diagram for a developing nation has a broad base that tapers quickly towards the top. This means that a larger percentage of the population is in the pre-reproductive age group and reproductive age group with a smaller percentage of the population in the post-reproductive age. These countries have a great chance of future population growth.
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.
