Macromolecules in a biological system

Question 1

Macromolecules I

Answer 1

Living organisms are composed of carbon and other elements bonded together to form organic macromolecules. Monomers from food are used to build these macromolecules. Macromolecules are large polymers, a chemical compound formed when covalent bonds link monomers in long, repeating chains.

Question 2

Macromolecules II

Answer 2

Covalent bonds in macromolecules are formed by endergonic removal of a water molecule. The chemical reaction is known as “dehydration” or “condensation synthesis” bonds can be broken by exergonic addition of water, known as hydrolysis (releases energy as bonds break between monomers). Perform different functions and are classified into 4 groups: carbohydrates, lipids, proteins, and nucleic acids.

Question 3

Element

Answer 3

Pure substances that cannot be broken into simpler substances.

Question 4

monomers

Answer 4

Molecules that can bond to similar or identical molecules to form a polymer. Are from food and are used to build these macromolecules in biological systems.

Question 5

Polymer

Answer 5

A substance composed of similar units bonded together. A chemical compound formed when covalent bonds link monomers in long, repeating chains.

Question 6

Dehydration reaction

Answer 6

A chemical reaction between two molecules in which a water molecule is released and a covalent bond forms, often requires an input of energy. Polymers are built as a result of this reaction.

Question 7

Hydrolysis reaction

Answer 7

A chemical reaction in which a water molecule cleaves a covalent bond to form two products, monomeric subunits of polymers are cleaved from a polymer by this reaction. Releases energy as bonds break between monomers.

Question 8

Carbohydrates I

Answer 8

Carbohydrates known as “sugars” or “starch” are found in all living organisms. Monomers join together to form Carbohydrates. General formula CnH2nOn. Carbohydrate monomers are typically 3,4,5, or 6 carbons long. Also known as “monosaccharides” or “simple sugars.” C6H12O6 is glucose a monosaccharide. Two monosaccharides joined by dehydration synthesis form disaccharides. Sucrose is a common disaccharide (one glucose monosaccharide and fructose monosaccharide).

Question 9

Polysaccharides

Answer 9

Carbohydrate polymers made of many sugar molecules. Formed by a number of linked monosaccharides. Plants store carbohydrates as the polysaccharide starch.

Question 10

Glycogen

Answer 10

Animals store the monosaccharide glucose in the form of polysaccharide glycogen. Glycogen is formed by dehydration synthesis and is stored mainly in the liver and muscles. Ex: when glucose is needed for energy production by a cell, glycogen is hydrolyzed into glucose.

Question 11

Oligosaccharides

Answer 11

Contain a small number of monosaccharides. They are found on the surface of cell membrane and function in cell recognition.

Question 12

Carbohydrates II

Answer 12

Can take on many forms and perform a variety of functions. They are linear, branched or helix shaped. Linear carbohydrates such as cellulose and chitin often form structures. Ex: cellulose forms rigid cell walls in plants—branched carbohydrates such as glycogen and amylopectin function in energy storage. Glycoproteins and glycolipids contain carbohydrates and other macromolecules that function in cell recognition.

Question 13

Lipids I

Answer 13

Are important structural, energy-storage, and hormone macromolecules. Oils and fats are not true polymers, not formed from one type of repeated monomer. Lipids are formed from a linear arrangement of carbon atoms and hydrogen atoms called “fatty-acid chains.” Attached to a glycerol molecule. Lipids are hydrophobic and nonpolar.

Question 14

Lipids II

Answer 14

Lipids are subdivided into four groups: fats and oils, waxes, phospholipids, and steroids, and are all insoluble in water. Each group has its own unique characteristics and functions.

Question 15

Lipids III

Answer 15

A fat molecule consists of a glycerol backbone and three fatty acid chains. The human body uses fats for energy storage, cushioning, and insulation. Fats are a dietary component found in oils, butter, and meat. Waxes usually contain long fatty acid chains connected to alcohols. Waxes are hydrophobic and are used by living things to stay dry. Waxes cover the feathers of birds and leaves of plants.

Question 16

Lipids IV

Answer 16

Phospholipids are two fatty acid chains attached to a phosphate molecule. One function is to form a semi-permeable membrane around cells. Help separate aqueous compartments in living things. Steroids have a four ring structure and include cholestrol, sex hormones, and hormones of adrenal cortex. Steroids often function as chemical messengers.

Question 17

Glycerol

Answer 17

A sugar compound that serves as a backbone for triglycerides and phospholipds.

Question 18

Hydrophobic

Answer 18

Water fearing

Question 19

Fatty acid

Answer 19

A molecule composed of a long hydrocarbon chain with a carboxylic acid group on one end.

Question 20

Proteins I

Answer 20

Proteins are polymers of long chains of amino acid monomers. Amino acids are composed of a central carbon, an amine group, a carboxylic acid, and a side group. The side group is shown as the R side chain. Each amino acid has different properties because of its side group. The link between amino acids is a covalent bond called a “peptide bond.”

Question 21

Protein II

Answer 21

Proteins have variety of shapes and functions. Fibrous, hydrophobic proteins like keratin and collagen( have hydrophobic amino acids and not soluble in water). Function as structural molecules in hair and nails. Globular proteins have hydrophilic surface amino acids and are soluble in water. They function as carrier molecules like hemoglobin , antibodies, and enzymes. Cell membrane proteins have a hydrophobic amino acids sandwiched between hydrophilic amino acids. Embedded in membranes where they function in transport or signal transfer. Proteins can be found in meat, eggs, beans.

Question 22

Protein III

Answer 22

Enzymes are important class of proteins that catalyze biochemical reactions without being consumed in the reaction. Can be exergonic (release energy) or endergonic (require energy). Typically supplied by ATP.

Question 23

Protein VI

Answer 23

Different cell types have different enzymes based on metabolic function of the cell. Enzyme activity is affected by environmental conditions such as temperature and ph level. Enzymes have an active site. Ex: pepsin is produced and secreted by stomach cells and initiates protein difestion in the stomach.

Question 24

Nucleic Acids I

Answer 24

Nucleic Acids are polymers made of linked nucleotides contain hydrogen, carbon, oxygen, nitrogen and phosphorous. Nucleotides have 3 components: nitrogenous base, sugar, and phosphate group. Two nucleic acids in living systems are deoxynucleic acid (DNA) and ribonucleic acid (RNA). DNA is a double stranded helix and stores genetic informaiton. Genes are made up of DNA. Some genes provide the instructions to make molecules called “proteins”. In humans genes contain a few hundred DNA bases to more than a million bases. Genes made of DNA are located on larger structures called chromosomes. Chromosomes are made of DNA and proteins are located in the nucleus of the cell. DNA contains nucleotides composed of deoxyribose sugar, one of four nitrogenous bases (adenine, guanine, cytosine, thymine) and a phosphate molecule.

Question 25

Nucleotides II

Answer 25

RNA consists of ribonucleotides containing ribose sugar, a nitrogenous base (adenine, guanine, cytosine, uracil), and is single stranded molecule. RNA helps to convert information stored in genes composed of DNA into proteins.There are 3 types of RNA molecules, Messenger RNA (mRNA) located in the nucleus of the cell transcribes the genetic code for a protein from the DNA template. It carries the genetic code out of the nucleus to ribosomal RNA (rRNA)located on ribosomes in cell’s cytoplasm. Transfer RNA (tRNA) brings amino acid dictated by mRNA’s code to the ribosome.Ribosome provides the catalytic environment necessary for peptide bonds to form. Ribosomes are the site of protein synthesis from amino acid monomers.

Question 26

Nucleic Acid III

Answer 26

The sequence of nucleotides in a nucleic acid is important in the process of building proteins. The sequence of nucleotides determines the specific protein synthesized. Errors in the precise sequence of nucelotides are mutations and interfere with proteins structure and function. Nucleic acids can be found in small amounts in all foods that contain cells.

Question 27

Ribonucleic Acid (RNA)

Answer 27

An important biological macromolecule that is present in all cells and controls the intermediate steps involved in protein synthesis.