Worksheet B2

what is the function of buffers?

A chemical or a combination of chemicals that keeps pH within normal limits. Buffers resist pH changes because they can take up excess hydrogen ions (H+) or hydroxide ions (OH−).

Polymers can be synthesized and broken down (see Figure 3.7). Which type of reaction synthesizes polymers and which type of reaction breaks down polymers?

Breakdown occurs when the monomers in a polymer separate because of a hydrolysis reaction

molecule

union of two or more atoms of the same element; also, the smallest part of a compound that retains the properties of the compound

biological macromolecules are polymers that are formed when ____ are joined by a ______ reaction

monomers, dehydration synthesis

sometimes _____ _____ undergoes complementary base pairing

nucleic acid

What are the monomers called?

nucleotide

amino acid is to protein as a ______ is to a nucleic acid

nucleotide

biological molecule

organic molecule in cells; carbohydrates, lipids, proteins, and nucleic acids

why are seeds coated with chitin?

protects them from attack by soil fungi

keratin, found in hair, fingernails, horns, and feathers is a ___

protein

monomer

small molecule that is a subunit of a polymer -- e.g. glucose is a monomer of starch

atom

smallest particle of an element that displays the properties of the element

element

substance that cannot be broken down into substance with different properties; composed of only one type of atom

what do all lipids have in common?

they are insoluble in water

hydrophobic

type of molecule that does not interact with water because it is nonpolar

hydrophilic

type of molecule that interacts with water by dissolving in water and/or by forming hydrogen bonds with molecules

what is the range of the pH scale?

0-14

what is the pH of neutral water?

7

What are the monomers of proteins? How many types exist?

Amino acids, 20 different amino acids.

what is the difference between an organic and inorganic molecule? give an example of each.

An organic molecule contains atoms of carbon and hydrogen. Organic molecules make up portions of cells, tissues, and organs An inorganic molecule does not contain carbon and hydrogen. Water (H2O) and table salt (NaCl) are examples of inorganic molecules. Examples of organic molecules include sucrose, cellulose, triglycerides, phospholipds, proteins and deoxyribonucleic acid

what is the relationship between monomers and polymers?

Certain biological molecules in cells are composed of a large number of the same type of subunits, called monomers. When many monomers join, the result is a polymer. A protein can contain hundreds of amino acid monomers, and a nucleic acid can contain hundreds of nucleotide monomers. How can polymers get so large? Just as a train increases in length when boxcars are hitched together one by one, so a polymer gets longer as monomers bond to one another.

Which of the 3 important omega-3 fatty acids may reduce the risk of Alzheimer disease?

DHA

what are the two types of nucleic acids?

DNA and RNA

what are the functions of nucleic acids?

DNA stores genetic information. Each DNA molecule contains many genes, and genes specify the sequence of the amino acids in proteins. RNA is the molecule that aids in transcribing and translating DNA into a protein

what is the difference between fats and oils?

Fats (such as bacon fat, lard, and butter) and oils (such as corn oil, olive oil, and coconut oil) In general, fats are solid at room temperature, while oils are liquid at room temperature.

what are the functions of lipids?

In animals, fats are used for both insulation and long-term energy storage. They are used to insulate marine mammals from cold arctic waters and to protect our internal organs from damage. Instead of fats, plants use oils for long-term energy storage. In animals, the secretions of oil glands help waterproof skin, hair, and feathers.

what are the functions of carbohydrates?

In living organisms, carbohydrates are almost universally used as an immediate energy source. However, for many organisms, such as plants and fungi, they also have structural functions. Carbohydrates may exist either as saccharide (sugar) monomers or as polymers of saccharides. Typically, the sugar glucose is a common monomer of carbohydrate polymers. The term carbohydrate may refer to a single sugar molecule (monosaccharide), two bonded sugar molecules (disaccharide), or many sugar molecules bonded together (polysaccharide).

how do plants and animals store glucose?

Plants store glucose as starch. The cells of a potato contain granules, where starch resides during winter until energy is needed for growth in the spring. N Animals store glucose as glycogen, which is more highly branched. Branching subjects a polysaccharide to more attacks by hydrolytic enzymes; therefore, branching makes a polysaccharide easier to break down. Spiraling makes these polysaccharides more compact.

what are some functions of proteins?

Support - Some proteins are structural proteins. Examples include the protein in spiderwebs; keratin, the protein that contributes to hair and fingernails; and collagen, the protein that lends support to skin, ligaments, and tendons. Metabolism Many proteins are enzymes. They bring reactants together and thereby act as catalysts, speeding up chemical reactions in cells. Enzymes are specific for particular types of reactions and can function at body temperature. Transport Channel and carrier proteins in the plasma membrane allow substances to enter and exit cells. Other proteins transport molecules in the blood of animals—for example, hemoglobin, found in red blood cells, is a complex protein that transports oxygen (Fig. 3.15b). Defense Some proteins, called antibodies, combine with disease-causing agents to prevent those agents from destroying cells and causing diseases and disorders. Regulation Hormones are regulatory proteins. They serve as intercellular messengers that influence the metabolism of cells. For example, the hormone insulin regulates the concentration of glucose in the blood, while human growth hormone (hGH) contributes to determining the height of an individual. Motion The contractile proteins actin and myosin allow parts of cells to move and cause muscles to contract (Fig. 3.15c). Muscle contraction enables animals to move from place to place and substances to move through the body. It also regulates body temperature.

Phospholipids arrange themselves as a bilayer in the membrane that surrounds a cell (Figure 3.13). Which part of the phospholipid molecule is hydrophilic and which part is hydrophobic?

The hydrophilic (polar) head group is soluble in water, whereas the two hydrophobic (nonpolar) tail groups are not. This causes the molecules to arrange themselves as a bilayer in the plasma membrane that surrounds a cell

what is the difference between saturated and unsaturated fats?

Unsaturated fatty acids have double bonds in the carbon chain wherever the number of hydrogens is less than two per carbon atom. Saturated fatty acids have no double bonds between the carbon atoms

Solutions with a pH higher than 7 have more OH- ions. What are these solutions called?

acid

A pH of 3 is

acidic

______ contribute hydrogen ions (H+) to a solution

acids

The shape of a protein determines its function. List 2 factors which may denature a protein.

acids and bases, rise in temperature

pH

algorithmic measure of the hydrogen ion concentration

Solutions with a pH lower than 7 have more H+ ions. What are these solutions called?

base

to maintain a constant pH, many organisms use ____ to regulate the hydrogen ion concentration

buffers

cellulose, the major component of plant cell walls is a __`

carbohydrate

list the four categories of biological molecules

carbohydrates, lipids, proteins, and nucleic acids

base

molecules tending to lower the hydrogen ion concentration in a solution and raise the pH numerically

acid

molecules tending to raise the hydrogen ion concentration in a solution and to lower its pH numerically

carbon can form a variety of molecules. What does this indicate about the function of carbon molecules?

ecause carbon is small and needs to acquire four electrons, carbon can bond with as many as four other elements. Carbon atoms most often share electrons with other carbon atoms. The C—C bond is stable, and the result is that carbon chains can be quite long. Hydrocarbons are chains of carbon atoms that are bonded only to hydrogen atoms. Any carbon atom of a hydrocarbon molecule can start a branch chain, and a hydrocarbon can turn back on itself to form a ring compound. Carbon can also form double bonds with itself and other atoms.

what is a very important monosaccharide?

glucose

what is an example of a monosaccharide?

glucose

what are two types of subunit molecules?

glycerol and fatty acids

a triglyceride contains ____ and ______

glycerol and three fatty acids

what is a benefit of adding cellulose to your diet?

in humans, cellulose has the benefit of serving as dietary fiber, which maintains regular elimination and digestive system health.

Carbon chains can var in ___, ____, ____

length, number of bonds, branching pattern

steroids such as cholesterol and sex hormones are ___

lipids

what is insoluble in water due to hydrocarbon chains?

lipids

polymer

macromolecule consisting of covalently bonded monomers.

homeostasis

maintenance of normal internal condition in a cell or an organism by mean of self regulating mechanisms

list 3 disaccharides

maltose, sucrose, and lactose