Carbohydrates and Proteins

​BIOMOLECULES

Carbohydrates and Proteins

A biomolecule is a chemical compound found in living organisms. These include chemicals that are composed of mainly carbon, hydrogen, oxygen, nitrogen, sulfur and phosphorus.

Biomolecules are the building blocks of life and perform important functions in living organisms.

There are four major categories of biomolecules:

1. CARBOHYDRATES

2. PROTEINS

3. LIPIDS AND FATS

4. NUCLEIC ACIDS

Carbohydrates, or carbs, are sugar molecules. Along with proteins and fats, carbohydrates are one of three main nutrients found in foods and drinks.

Our body breaks down carbohydrates into glucose. Glucose, or blood sugar, is the main source of energy for your body's cells, tissues, and organs. Glucose can be used immediately or stored in the liver and muscles for later use.

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Carbohydrates

Carbohydrates are composed of (C) carbon, (H) hydrogen and (O) oxygen elements (1:2:1 ratio).

Multiple Choice

Which of the following elements is NOT present in the composition of a carbohydrate?

• A. oxygen

• carbon

• hydrogen

• nitrogen

They are also called simple carbohydrates because they are in the most basic form. They can be added to foods, such as the sugar in candy, desserts, processed foods, and regular soda. They also include the kinds of sugar that are found naturally in fruits, vegetables, and milk.

SUGARS

Carbohydrates can be classified according to their chemical structure as:

1. Monosaccharides: One molecule sugar/simple sugars.
   Examples:

   • Glucose

   • Fructose (Fruit Sugar)

   • Galactose (milk sugar)

2. Dissacharides:Two molecule of monosaccharide linked together.
   Examples:

   • Sucrose (Table sugar) = Glucose+Fructose.

   • Lactose (milk sugar) = Glucose+Galactose

   • Maltose (malt sugar) = Glucose+Glucose

3. Polysaccharides: Number of monosaccharides linked together
   Examples:

• Starch-They are complex carbohydrates, which are made of lots of simple sugars strung together. Your body needs to break starches down into sugars to use them for energy. Starches include bread, cereal, and pasta. They also include certain vegetables, like potatoes, peas, and corn.

• Glycogen

• cellulose

Multiple Choice

The following are monosaccharides except ___

• sucrose

• glucose

• fructose

• galactose

Carbohydrates provide glucose that body cells can use for energy. Excess glucose beyond what the body needs for immediate energy is converted into glycogen, a storage form of carbohydrate, or converted into fat and stored in body fat cells.

 

Glucose provides energy for all body cells. The brain and nerve cells use only glucose for energy. If blood glucose levels fall too low, glycogen is broken down to provide glucose. The body can only store enough glycogen to provide about a half-day’s supply of energy. Since glycogen stores are only enough to provide energy for a short time, the body needs a frequent supply of carbohydrates.

Multiple Choice

Which of the following statement is not correct?

• When we eat, glucose level rises.

• Excess glucose is converted to glycogen

• Glycogen is converted to glucose when glucose level is low

• Glycogen stored in our liver provide a long term supply of energy

2. PROTEINS

Proteins are macromolecules composed of amino acids. Amino acids are commonly called protein’s building blocks. Proteins are crucial for the nourishment, renewal, and continuance of life. Proteins contain the elements carbon, hydrogen, and oxygen just as carbohydrates and lipids do, but proteins are the only macronutrient that contains nitrogen.

Proteins are the building blocks of life. Every cell in the human body contains protein. The basic structure of protein is a chain of amino acids.

You need protein in your diet to help your body repair cells and make new ones. Protein is also important for growth and development in children, teens, and pregnant women.

Multiple Choice

What element is present in proteins but not in carbohydrates and lipids?

• hydrogen

• carbon

• nitrogen

• oxygen

Proteins play both structural and dynamic roles. They help form many of the structural features of the body including hair, nails and muscles. Myosin is the protein that allows movement by contraction of muscles. Proteins are also present as a major component of cell membranes. Being part of cell membranes, proteins act as carriers or channels, facilitating the movement of ions and molecules in and out of the cells. Ions like sodium, potassium and chloride, molecules like glucose are maintained at proper concentration for cells to function normally. Proteins also acts as catalyst. A large group of proteins, known as enzymes, enable the cells to carry out chemical reactions fast. In order for the organism to maintain growth and survival, the food being consumed must be converted to energy at an appreciable rate.

Multiple Choice

Which of the following statements is NOT true about proteins?

• Proteins are made up of amino acids.

• Proteins are essential for the development of skin, teeth and bones

• Protein is the only nutrient that can build, repair and maintain body tissues

• Proteins control the body’s internal climate with the goal of maintaining constant temperature.

Multiple Choice

The following are important functions of proteins in the body except _______

• growth and maintenance

• maintain body temperature

• catalyze reactions

• provide structure

Multiple Choice

Some proteins are hormones, which are chemical messengers that aid communication between your cells, tissues and organs.

• True

• False

• either true or false

• sometimes true