Provided that there's no diagram, most molecules have particular areas on the molecules, called the "active area" that act as a lock to a particular substrate's molecular structure, providing the key.
An enzyme's active area is only able to be "unlocked" by a certain substrate's "key".
Basement membranes are thin, dense sheets of specialized, self- assembled extracellular matrix that surround most animal tissues. The basement membrane is a fibrous matrix composed primarily of glycoproteins, type IV collagen, and laminin that are secreted by the epithelial cells.
Answer:
D. Nucleus.
Explanation:
A cell can be defined as the structural, fundamental, biological and functional unit of life. Cells are found in all living organisms because they are the basic unit of life. A unicellular organism refers to a living organism that possess a single-cell while a multicellular organism has many (multiple) cells.
Some examples of cell organelles found in all living organisms such as trees, birds, and bacteria include; nucleus, cytoplasm, cell membrane, golgi apparatus, mitochondria, lysosomes, ribosomes, chromosomes, endoplasmic reticulum, vesicles, etc.
Proteins on the surface of vesicles determine where the vesicles go.
The nucleus is the cell organelle which provides the instructions for these proteins. It controls all the activities taking place in the cell and the synthesis of proteins.
Chromatin is the lose form of genetic material & the "normal state" of DNA, RNA, and protein in the nucleus and in the cells.
Chromosomes are a condensed form of chromatin. Chromatin becomes chromosomes in the Prophase of Mitosis and Prophase 1 and Prophase 2 of Meiosis. It loosens again in the Telophase in Mitosis and Telophase 1 and Telophase 2 in Meiosis.
Sister Chromatids are made when chromosomes replicate during the cell cycle. The replication leads to the formation of the chromatids. The chromatids are joined by a single centromere. They separate during Anaphase 2 of meiosis.
I hope that this helps! Sorry if it doesn't I tried my best to explain!