Proteins are the macromolecules made of hundreds of amino acids. Proteins are most varied class of biological molecules and show the greatest variety of structures. Many have detailed three-dimensional folding patterns that result in a compact form, but others do not fold up at all and they are in random conformations. The function of proteins depends on their structure.
The secondary structure of protein fold together to form the 3D arrangement of a polypeptide chain that results into Tertiary structure which is a functional protein.
excretory system: removes waste from blood.
respiratory system: obtains oxygen so the energy in the nutrients can be extracted.
circulatory system: transports nutrients from small intestine to the othet tissues.
nervous system: regulates and controls digestive functioning.
( Am not completly sure, but i think this is the answer)
It starts with a seed, than when the seed is on the ground it germinates.
Answer:
1. Providing structure --> Collagen makes skin strong yet flexible.
2. Maintaining homeostasis --> Insulin controls the concentration of sugar in the blood.
3. Fighting Disease --> IgA prevents the buildup of viruses and bacteria in the gut.
4. regulating chemical reactions --> Pepsin works in the stomach to speed up the breakdown of food.