Answer:
a. osmosis (water must pass through the cell membrane so it is osmosis) b. neither (the saliva is secreted) c. diffusion (the dye doesn't pass through a membrane) d. diffusion"
Explanation:
I'm not sure, but I hope it helps.
Enzymes are catalysts that can be used more than once. If a substance needs to get broken down then it can use the corresponding enzyme to attach itself and break it down into simpler substances. After this is gone, the next substance might come up and attach itself to the enzyme like a lock-and-key model.
Therefore the answer is A) Enzymes accelerate chemical reactions without getting used up in the process.
Answer:
C. RNA polymerase binding to a region near the gene, called the promoter
Protein structure is the three-dimensional arrangement of atoms in a protein molecule. Proteins are polymers — specifically polypeptides — formed from sequences of amino acids, the monomers of the polymer. A single amino acid monomer may also be called a residue (chemistry) indicating a repeating unit of a polymer. Proteins form by amino acids undergoing condensation reactions, in which the amino acids lose one water molecule per reaction in order to attach to one another with a peptide bond. By convention, a chain under 30 amino acids is often identified as a peptide, rather than a protein.[1] To be able to perform their biological function, proteins fold into one or more specific spatial conformations driven by a number of non-covalent interactions such as hydrogen bonding, ionic interactions, Van der Waals forces, and hydrophobic packing. To understand the functions of proteins at a molecular level, it is often necessary to determine their three-dimensional structure. This is the topic of the scientific field of structural biology, which employs techniques such as X-ray crystallography, NMR spectroscopy, and dual polarisation interferometry to determine the structure of proteins.
Protein structures range in size from tens to several thousand amino acids.[2] By physical size, proteins are classified as nanoparticles, between 1–100 nm. Very large aggregates can be formed from protein subunits. For example, many thousands of actin molecules assemble into a microfilament.
A protein may undergo reversible structural changes in performing its biological function. The alternative structures of the same protein are referred to as different conformational isomers, or simply, conformations, and transitions between them are called conformational changes.
