Answer:
Reactions require an input of energy to initiate the reaction; this is called the activation energy (EA).
Activation energy is the amount of energy required to reach the transition state.
The source of the activation energy needed to push reactions forward is typically heat energy from the surroundings.
For cellular reactions to occur fast enough over short time scales, their activation energies are lowered by molecules called catalysts.
Enzymes are catalysts
Answer:
he cell membrane is the semipermeable membrane of a cell that surrounds and encloses its contents of cytoplasm and nucleoplasm. The cell membrane separates the cell from the surrounding interstitial fluid, the main component of the extracellular fluid.
Explanation:
The type of proteins that can function as the chemical messengers or as the receptors in the plasma membrane is a communication proteins; option A.
Proteins are large macromolecules composed of chains of amino acid units linked together by peptide bonds.
Proteins serve various functions such as:
communication
transport
defensive
enzyme
Communication of proteins such as the hormones can be function as the chemical messengers or as receptors in the plasma membrane.
Proteins are made up of hundreds or the thousands of the smaller units called as amino acids, which are attached to one another in the long chains. There are about 20 different types of amino acids that can be combined to make a protein.
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Terrestrial Ecosystem- Is a type of ecosystem found only on biomes.
Six primary terrestrial ecosystems exist: Tundra, Taiga, Temperate Deciduous Forest , Tropical Rain Forest, Grassland and Desert