1. First, find out what nutrients Janine and Mitchell are talking about. Using a biology textbook and the resources listed, describe what the following molecules are and what they are used for in the human body. List some specific examples of each. Also list major dietary sources of each. a. Proteins b. Carbohydrates c. Fats 2. Janine made this statement: "... if your brain doesn't get carbs-well, glucose, anyway-you get really cranky. You have to have enough carbs." Find out if Janine is right. How does the nervous system use glucose? 3. Janine also said: "If you eat way too much protein and not enough carbs you can ruin your kidneys forever because of all the nitrogen you have to process breaking down the protein." Find out if Janine is right about this, too. Check a biology textbook for information on protein, fats, and carbohydrates. To find out how these substances can be used for energy, look up information on cellular respiration. 4. The words "calorie" and "energy" come up a lot in discussions of diet and nutrition. Use a biology textbook to define both of these terms. Then suppose you found a product that was labeled "calorie-free energy drink." Why would that label be misleading? 5. Which substances supply energy to the human body?

1. (a) Protein: Protein is a macronutrient composed of amino acids, which are organic compounds made of carbon, hydro, nitrogen, oxygen or sulphur. It is needed by the body to build and repair tissues, to make enzymes, hormones, and other body chemicals. Protein is an important building block of bones, muscles, cartilage, skin, and blood. Protein is found in animal, legumes and nuts. Good sources of protein include cowpea,eggs, chicken Breast, cottage cheese, yogurt, milk

(b)Carbohydrate: Carbohydrates are macronutrients that contain carbon, hydrogen and oxygen. Carbohydrate is found in fruits, grains, vegetables and milk products. The functions of carbohydrate include providing energy and regulation of blood glucose, breakdown of fatty acids and prevention of ketosis and provision of dietary fibre. Food sources of carbohydrate are oat, buckwheat, sweet potato, cassava, yam, banana

(c) Fats: Fat are food molecules consisting of carbon and hydrogen. Fats are soluble in organic solvents and insoluble in water. Examples of fats include cholesterol, phospholipids, and triglycerides. Fats give the body energy and support cell growth. They also help protect body organs and help keep the body warm. Fats help the body absorb some nutrients and produce important hormones, too. Foods rich in fats include salmon, avocados, olives, and walnuts, and vegetable oils like soybean, corn, canola, and olive oil, butter and cheese.

2. Janine is right because the brain performs many complicated roles that use up a lot of energy. The brain uses half of the total glucose in the human body. Some of the brain functions such as learning, thinking, learning, and memory are based on the levels of glucose in the brain. However, the levels of glucose in the body should be balanced, High levels cause insulin resistance. Insulin regulates blood sugar. If the brain doesn`t get carbohydrates well, one becomes cranky.

Brain cells need glucose to fuel cellular activities. Glucose metabolism provides the fuel for physiological brain function through the generation of ATP, the foundation for neuronal and non-neuronal cellular maintenance, as well as the generation of neurotransmitters.

(3) Janin is wrong because although excess protein can cause damage in people with preexisting kidney disease, there's been no record of major studies linking high protein intake to kidney damage in healthy individuals.

Cellular respiration is the breakdown of food molecules to release energy in the form of ATP. Carbohydrates, fats, and proteins can all be used as fuels in cellular respiration. The energy released is needed for growth, repair and movement.

(4) Calorie: calorie is a unit of energy. We can get calories from a variety of food sources, such as, fats, proteins, carbohydrates or sugars. Calories can also be said to be the amount of energy released when the body breaks down food.

Energy: this is power derived from the utilization of chemical substances found in food. The body needs energy to function in its optimal state.

The label 'energy free drink' is misleading because it may contain sugar alcohol such as sorbitol or mannitol which is not calorie-free and may cause digestive upset.

(5) Carbohydrates, fats and proteins supply energy to the human body.

cardiovascular system

mark as brainliest

synovial joints are characterized by the presence of a joint cavity. the walls of this space are formed by the articular capsule, a fibrous connective tissue structure that is attached to each bone just outside the area of the bone’s articulating surface. the bones of the joint articulate with each other within the joint cavity.

friction between the bones at a synovial joint is prevented by the presence of the articular cartilage, a thin layer of hyaline cartilage that covers the entire articulating surface of each bone. however, unlike at a cartilaginous joint, the articular cartilages of each bone are not continuous with each other. instead, the articular cartilage acts like a teflon® coating over the bone surface, allowing the articulating bones to move smoothly against each other without damaging the underlying bone tissue. lining the inner surface of the articular capsule is a thin synovial membrane. the cells of this membrane secrete synovial fluid (synovia = “a thick fluid”), a thick, slimy fluid that provides lubrication to further reduce friction between the bones of the joint. this fluid also provides nourishment to the articular cartilage, which does not contain blood vessels. the ability of the bones to move smoothly against each other within the joint cavity, and the freedom of joint movement this provides, means that each synovial joint is functionally classified as a diarthrosis.

outside of their articulating surfaces, the bones are connected together by ligaments, which are strong bands of fibrous connective tissue. these strengthen and support the joint by anchoring the bones together and preventing their separation. ligaments allow for normal movements at a joint, but limit the range of these motions, thus preventing excessive or abnormal joint movements. ligaments are classified based on their relationship to the fibrous articular capsule. an extrinsic ligament is located outside of the articular capsule, an intrinsic ligament is fused to or incorporated into the wall of the articular capsule, and an intracapsular ligament is located inside of the articular capsule.

at many synovial joints, additional support is provided by the muscles and their tendons that act across the joint. a tendon is the dense connective tissue structure that attaches a muscle to bone. as forces acting on a joint increase, the body will automatically increase the overall strength of contraction of the muscles crossing that joint, thus allowing the muscle and its tendon to serve as a “dynamic ligament” to resist forces and support the joint. this type of indirect support by muscles is very important at the shoulder joint, for example, where the ligaments are relatively weak.

additional structures associated with synovial joints

a few synovial joints of the body have a fibrocartilage structure located between the articulating bones. this is called an articular disc, which is generally small and oval-shaped, or a meniscus, which is larger and c-shaped. these structures can serve several functions, depending on the specific joint. in some places, an articular disc may act to strongly unite the bones of the joint to each other. examples of this include the articular discs found at the sternoclavicular joint or between the distal ends of the radius and ulna bones. at other synovial joints, the disc can provide shock absorption and cushioning between the bones, which is the function of each meniscus within the knee joint. finally, an articular disc can serve to smooth the movements between the articulating bones, as seen at the temporomandibular joint. some synovial joints also have a fat pad, which can serve as a cushion between the bones.