Nutrition

Question 1

what is a calorie?

Answer 1

the amount of energy needed to raise the temperature of 1 kilogram of water 1 degree celsius

Question 2

what are the six fundamental nutrients and which ones generate energy when consumed?

Answer 2

proteins, lipids, carbohydrates, vitamins, minerals, and water are the six fundamental nutrients; proteins, lipids, and carbohydrates generate energy when consumed

Question 3

why is water so vital to the survival of an animal?

Answer 3

• major component of blood
• found inside and outside all cells
• lubricant for body tissues
• transportation medium
• temperature regulation
• maintains homeostasis

Question 4

what are the three categories of carbohydrates?

Answer 4

sugars, starches, and cellulose

Question 5

what are the four major categories of lipids?

Answer 5

neutral fats, phospholipids, steroids, and other lipoid substances

Question 6

what is the difference between a saturated and an unsaturated fat? why is this difference important nutritionally?

Answer 6

saturated fatty acids have single bonds between the carbon atoms and can accommodate the greatest number of hydrogen atoms attached to the chain of carbon atoms, they also tend to have long chains and are primarily found in meat and dairy foods such as milk, cream, cheese, lard, and butter; unsaturated fatty acids have one or more double bonds between the carbon atoms and can accommodate fewer hydrogen atoms, these are found in seeds, nuts, and most vegetables

Question 7

what is an essential fatty acid?

Answer 7

essential fatty acids are ones that the body cannot manufacture and must be provided in the diet.

Question 8

what are steroids?

Answer 8

lipids that are dramatically different from neutral fats, made of four interlocking rings of hydrocarbons; they include cholesterol, bile salts, sex hormones, and hormones released in the cortex of the adrenal gland

Question 9

what is the principal building block unit of proteins and how are they arranged?

Answer 9

amino acids are the principal building blocks of proteins, they are arrange by one amino acid links to the basic group on the next, forming a peptide bond

Question 10

what are the four basic components of amino acids?

Answer 10

amino acids are composed of a central carbon atom, an amino group (NH2), a carboxyl group (COOH), and a variety of side chains (“R” group); differences in the “R” group make each amino acid unique

Question 11

what are the amino acids called that can not be made in the body so they must be found in the diet?

Answer 11

essential amino acids cannot be synthesized in the body; taurine is an essential amino acid for cats, and glycine is essential for birds

Question 12

what is cellular metabolism?

Answer 12

it is all the biochemical events involved in building molecules and breaking down nutrients, manufacturing, packaging, and excreting; making proteins is one very important example of cellular metabolism

Question 13

what are the two categories of cellular metabolism?

Answer 13

anabolism and catabolism

Question 14

what is the first stage of cellular metabolism called?

Answer 14

the first stage of catabolism is called hydrolysis, it is when energy is produced

Question 15

is energy produced or consumed during anabolic process?

Answer 15

energy is consumed during the anabolic process; examples include the production of fat molecules by combining glycerol and fatty acid molecules, and the creation of proteins by joining amino acids

Question 16

what cellular process represents the largest demand for protein and enzymes?

Answer 16

metabolic turnover

Question 17

why are enzymatic reactions considered highly specific?

Answer 17

enzymatic reactions are highly specific because one enzyme reacts only with one substrate or combination of substrates.

Question 18

what is a substrate and what is a product?

Answer 18

each enzyme reacts with a particular molecule called a substrate to produce a new molecule called a product

Question 19

why is the total number of enzymes present in the body relatively low when compared with the number of metabolic reactions?

Answer 19

enzymes are recycled and used over and over again, so once an enzyme has catalyzed one reaction, it is free to catalyze another reaction, in this way, a few enzymes can carry out many metabolic reactions

Question 20

what is the energy of activation in a biochemical reaction?

Answer 20

the energy of activation is the energy needed to initiate a biochemical reaction

Question 21

what is a catalyst?

Answer 21

a catalyst is a substance that speeds up a reaction; enzymes are catalysts because they speed up reactions by lowering the activation energy

Question 22

what are the characteristics of an enzyme?

Answer 22

• an enzyme’s name ends with the suffix -ase
• the enzyme is usually named for the substrate on which it acts
• the name of the enzyme may also indicate the kind of reaction that the enzyme initiates

Question 23

what is a cofactor?

Answer 23

elements such as iron, zinc, or copper, that are needed to complete the shape of a binding site; magnesium ion is a cofactor in reactions that involve the transfer of a phosphate group and is therefore found in virtually all cells

Question 24

how might vitamins play a role in enzyme driven reactions?

Answer 24

vitamins are nonprotein organic substances whose derivatives may act as cofactors, specifically called coenzymes; they may be bound temporarily or permanently to the enzyme and are usually located near the active site

Question 25

how is energy stored in molecules and when is it released?

Answer 25

energy is stored in the atomic bonds of molecules such as ATP, NADH, and FADH2, energy is released when part of the molecule is broken off

Question 26

where does carbohydrate metabolism begin in non-ruminant animals?

Answer 26

with the breakdown of glycogen or glycerol in the liver

Question 27

what part of carbohydrate metabolism occurs in the cytoplasm?

Answer 27

glycolysis breaks down glucose to form pyruvate in the cytoplasm

Question 28

under what conditions is lactic acid formed in muscle cells?

Answer 28

when oxygen is depleted

Question 29

how many biochemical steps are involved in glycolysis and does it require oxygen?

Answer 29

glycolysis involves 10 steps, no, it does not require oxygen

Question 30

cellular respiration is composed of what two parts?

Answer 30

anaerobic (glycolysis) and aerobic respiration (krebs cycle and the electron transport chain)

Question 31

how does the membrane structure of the mitochondria assist in the process of cellular respiration?

Answer 31

the inner membrane of the mitochondrion houses a series of cytochrome molecules, which make up the electron transport system, as electrons are passed from one cytochrome molecule to another, energy is released and used to transport protons from the mitochondrial matrix across the inner membrane to the intermembrane space, because protons are positive, this establishes a positive charge on the outside of the inner membrane relative to the matrix side, the electrical gradient that is established is a form of stored (potential) energy, energy is released when protons rush back into the mitochondrial matrix

Question 32

what role does oxygen play in the electron transport system?

Answer 32

at the end of the electron transport chain, oxygen accepts the low-energy electrons, joins with hydrogen ions, and forms water (H2O); oxygen is the final acceptor of the electrons

Question 33

what is oxidative phosphorylation?

Answer 33

the process in which ATP is produced as electrons are transferred from NADH or FADH2 to O2 by a series of electron carriers in the electron transport chain; this is the major source of ATP in aerobic organisms

Question 34

what is the maximum number of ATP molecules the can be formed from the catabolism of one molecule of glucose?

Answer 34

38

Question 35

what is transamination?

Answer 35

when the amine group from an amino acid is transferred to a different keto acid; in the process, a new and different amino acid is made

Question 36

what is the most common carbohydrate found in blood?

Answer 36

glucose

Question 37

what is deamination?

Answer 37

when the amine group from an amino acid is removed from the amino acid molecule forming one molecule of free ammonia and one keto acid molecule