Chapter 6-the Proteins and Amino Acids

________ are unique among the energy nutrients in that they possess ________-containing _____ groups and are composed of __ different amino acid units. of the __ amino acids, some are ________ and some are ________ only in special circumstances

_____ ____ link into long strands that coil and fold to make a wide variety of different ________

Each type of ______ has a distintive sequence of _____ ____ and so has great specificity. Often, cells __________ in synthesizing particular types of ________ in addition to the _______ necessary to all cells. _________ can greatly affect _______ ________.

________ can be _________ by_____,______, _______, _________, or the salts of _____ _______. ___________ begins the process of __________ food protein and can also _______body proteins.

The cells of the ______ _________complete ________, absorb _______ _____ and some larger _______,and release them into the ___________ for use by the body's cells.

The body needs ______ _____ _____to grow ___ cells and to ________ worn-out ones.

_________ are proteins that _______against foreign proteins and other foreign substances within the body.

Proteins help to regulate the body's _________ and ______.

Proteins buffer the blood against excess acidity or alkalinity.

Proteins that clost the blood prevent death from uncontrolled bleeding.

When insufficient carbohydrate and fat are consumed to meet the body's energy need, food protein adn body protein are sacraficed to supply energy. The nitrogen part is removed from each amino acid, and the resulting fragment is oxidized for energy. No storage form of amino acids exists in the body.

Amino acids can be metabolized to protein, nitrogen plus energy, glucose, or fat. They will be metabolized to protein only if sufficient energy is present from other sources. The diet should supply all essential amino acids and a full measure of protein according to guidelines.

The body's use of a protein depends in part on the user's health, the protein quality, and the other nutrients and energy taken with it. Digestibility of protein varies from food to food, and cooking can improve or impair it.

A protein's amino acid assortment greatly influences its usefulness to the body. Proteins lacking essential amino acids can be used only if those amino acids are present from other sources.

The amount of protein neede daily depends on size and stage of growth. The DRI recommeneded intake for adults is .8 gram of protein per kilogram of body weight.