Answer:
The mechanisms of transport across the cell membrane are as follow: 1- simple diffusion, 2- facilitated diffusion, 3- primary active transport and 4-secondary active transport
Explanation:
The cell membrane is a selectively permeable structure capable of transporting substances by different mechanisms. Simple diffusion is a type of passive transport (i.e. does not require energy) where non-polar molecules (e.g. O2, CO2) pass across the membrane by a process that does not require energy from the cell. Facilitated diffusion is another type of passive transport where larger polar molecules (e.g., glucose and amino acids) pass across the membrane by using specific transmembrane integral proteins. On the other hand, primary active transport is a type of active transport that uses chemical energy (e.g., ATP) to move substances such as metal ions (Na+, K+, Ca2+) across the cell membrane against their concentration gradient. Finally, secondary active transport is another type of active transport where transporter proteins are used to couple the movement of ions (e.g., H+ protons) down their electrochemical gradient to the transport of another ions/solutes against their concentration/ electrochemical gradient.
Cell wall.
Made of cellulose and acts as a stronger cell membrane in a plant cell
Answer:
Similarly, enzymes can only function in a certain pH range (acidic/alkaline). Their preference depends on where they are found in the body. For instance, enzymes in the intestines work best at 7.5 pH, whereas enzymes in the stomach work best at pH 2 because the stomach is much more acidic.
The organelles would create a basic protein that could be modified to move chromatids during metaphase is the histine protien which is secreted from the RNA's.
<u>Explanation:</u>
Histone protein is the protein that is associated with the chromosome. The chromatin fibres get condensed into chromosomes on these proteins.
The chromatin fibre i.e. the DNA fibre gets to wrap itself around the histone octamer which is formed of two units of each of Histone H2A H2B H3 and H4. Then the H1 protein seals the turn and thus a chromosome is formed. These histone are produced in the S-phase of the cell cycle. This protein is transcribed into m-RNA's and then translated into protein.
The correct answer is that ferns have two part in their life cycle: Diploid phase and haploid phase
The life cycle of a fern has two parts: sporophyte stage and gametophyte stage. The gametophyte stage of ferns are haploid which releases gametes and the sporophyte stage are diploid that produces spores. This kind of life cycle is known as the "alternation of generation".
