Criado por Alecea Sin
aproximadamente 9 anos atrás
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Questão | Responda |
What are proteins? | -Proteins are required for growth. -Amino Acids are the building blocks of proteins -Proteins are made up of polypeptides and folded into a three-dimensional shape. -The different types of amino acids in a polypeptide determines the shape of the protein. |
What is glycogen made up of? | Made up of chains of glucose |
What are the two important biological functions of a polysaccharide and their examples? | -Energy Storage (starch and glucose) -Structural Support (cellulose) |
What are carbohydrates? | -Carbohydrates are the major source of energy for cells. -Carbohydrates are composed of the elements carbon, hydrogen, oxygen. |
What are the three types of Carbohydrates? | -Monosaccharides -Disaccharides -Polysaccharides |
What are 3 functions of proteins? | -Enzymes are proteins that help speed up chemical reactions. -Proteins help provide structure and support for cells. -Antibodies are proteins that help defend and protects the human body from viruses and bacteria. |
Describe starch. | -Made up of chains of glucose. -Most animals can digest starch. -Energy storage. |
Describe cellulose. | -Long chains of glucose units. -A major structural component in plant cell wall. |
Describe glycogen. | -Made up of chains of glucose. -A storage polysaccharide in animals. -Stored in muscle and liver. -Can be broken down readily to release energy. |
What happens when a protein loses its three-dimensional shape? | The active functional protein will become denatured. |
What causes a denatured protein? | 1) Heating 2) Change in acidity or alkanity |
What happens when a protein is denatured? | It loses its function forever. (Denaturation is irreversible) |
What happens when there is too much protein? | Protein will be turned into glycogen as an energy storage and will then turn into fats when there is too much glycogen. |
Describe fats. | -The body uses fats as a source of energy. -Fats contain more than twice as much energy as carbohydrates and proteins. -Fats cushion vital organs in mammals, insulated against heat loss, and reduce water loss. -Animals store more energy (glycerol) with less weight than plants which uses starch, a bulky form of energy storage. |
What are fats made up of? | Fats are made up of glycerol and three long chains of fatty acids. Therefore known as triglycerides. -The fatty acid tails are insoluble in water (hydrophobic). Therefore fats are insoluble in water. |
What are the differences between saturated and unsaturated fats? | 1) Saturated Fats: Usually a solid at room temperature. Unsaturated fats: Usually a liquid at room temperature. 2) Saturated fats: Fatty acid chains are straight. Unsaturated fats: Fatty acid chains are bent in some areas. Example: Saturated fats: Beef fat Unsaturated fats: Linseed oil |
Describe vitamins, minerals and fibre. | -Neccessary for the maintenance of health and well-being. -Required in tiny amounts and do not need to be digested to be absorbed. -Fibre is indigestible and is required for preventing constipation. |
What are enzymes? | Enzymes are biological catalysts that speeds up chemical reactions in livings things and are not changed or destroyed by the reactions. |
What is a 'catalyst'? | A catalyst is any substance that works to accelerate a chemical reaction. |
What are the two types of enzymes? | -Reactions that break down substances are called catabolic reactions. The catabolic enzymes speed up the chemical reaction. Example: Amylase breaks down starch into maltose. -Reactions that build up or repair substances are called anabolic reactions. These are anabolic enzymes. |
Describe the lock-and-key hypothesis. | When the chemicals involved in a reaction (the substrates) get near an enzyme molecule, they "fit" into a part of the molecule called the active site, like a key in a lock. The enzymes is shaped so that the important parts of each chemical are close enough to each other to react together. When the reaction has occurred, the new chemicals (the products) do not fit in the lock and are released. This leaves the enzyme free to catalyze another reaction. |
Describe enzymes. | -Enzymes are made up of proteins. -They are all biological catalysts. They speed up a reaction without being used up; this means they can be used over and over again. -Enzymes are affected by temperature (excessive heat), acidity and alkanity. -Enzymes are specific and control only one reaction. -Plays an important role in physical and chemical digestion. |
Give 3 examples of monosaccharides, disaccharides, and polysaccharides. | -Monosaccharides: glucose, fructose, galactose. -Disaccharides: maltose, sucrose, galactose. -Polysaccharides: starch, glycogen, cellulose. *All are reducing sugars except sucrose! |
Will more enzymes affect the rate of reaction? | Yes, the more the amount of enzymes will decrease the time take for reaction to complete but only to a maximum amount. This is because there are more active sites present. |
Will the amount of substrates affect the time of reaction? | Yes, the more the number of substrates, the more time taken for the reaction to complete. This is because the enzymes need to catalyse more substrates into more products. |
Will the amount of temperature affect the rate of reaction? | Yes, enzyme activity increased with higher temperature, but only until an optimum temperature. (Optimum temperature for body enzymes are 39-41degrees and will denature from there. |
Will the size of the container affect the rate of reaction? | Yes, the bigger the container the slower the time taken to complete the reaction. This is because there is a lower collision rate between particles in a bigger space. |
Will the PH affect the rate of reaction? | Yes, enzymes are PH sensitive and will only work at a narrow PH range. |
What is pectin? | Pectin is a polysaccharide found in plant cell walls. |
What is pectinase? | Pectinase is an enzyme that is able to break down pectin, thereby causing the breakdown of the plant cell wall. This causes the cells to release the juice inside more quickly. |
Define digestion. | Digestion is the break down of complex food molecules with smaller, simpler and diffusible molecules so that they can be absorbed into the body. |
Name the process that allows food substances to move from the mouth cavity to the colon and describe how it works. | -Peristalsis. -Rhythmic war-like contractions of the muscles that propels food in one direction. |
Describe two ways in which the small intestine is adapted for absorption. | -Numerous villi to increase sirface area for food absorption. -Thin-walled so food can be absorbed easily. |
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