8. (F) Facilitated diffusion: For water to travel across the cell membrane at a substantial rate, the water molecules travel through protein channels known as aquaporins.
9. (S) Simple diffusion: While water molecules are polar, they are also very small. One fact not mentioned in the video is that some water molecules are able to squeeze directly through the phospholipid bilayer due to their small size.
10. (S) Simple diffusion: Charged ions are traveling through a cell membrane with the concentration gradient.
11. (A) Active transport: Cells lining the gut need to take in glucose, but at a certain time, the concentration of extracellular glucose is lower than the concentration already stored in the cells.
12.(F) Facilitated diffusion: At a certain time, glucose is in a high concentration outside of a cell and needs to travel through the membrane into the cell.
The above choices are made based on the basic definitions of active transport, facilitated diffusion and simple diffusion.
Active transport: The movement of the ions or molecules to a region having higher concentration across the membrane requiring the help of energy or enzymes is active transport.
Facilitated diffusion: This type of transport involves passive movement of the molecules or is a type of passive transport where the movement of the molecules takes place from higher to lower concentration region occurs with the aid of a carrier molecule such as a transport or carrier protein.
Simple diffusion: This process involves movement of ions or molecules from high concentration region to low concentration region through a semipermeable membrane.
Answer:
the particles have low energy and are able to mive and past each other
1. substrate
2. active site
3. reaction
Answer:
This question lacks options, the options are:
A. The sequence of DNA determines the structure of lipids, which produce phenotypes.
B. The sequence of DNA determines the structure of proteins, which produce phenotypes.
C. The sequence of DNA determines the structure of phosphates, which produce phenotypes.
D. The sequence of DNA determines the structure of carbohydrates, which produce phenotypes.
The answer is B.
Explanation:
DNA is the genetic material found in the genome of living organisms. DNA holds the information needed for the synthesis of useful products in an organism. DNA contains segments called GENES that encodes the biological molecule, PROTEINS, which is responsible for the trait exhibited by organisms.
An example of trait in humans is human color, which is encoded by DNA. However, this DNA does not directly produce hair color in humans but the information held in it undergoes expression to produce protein called MELANIN, which is responsible for the hair color trait. Hence, the sequence of DNA determines the structure of proteins, which produce phenotypes (hair color).