C1: The Chemical Basis Of Life

Question 1

What is electronegativity?

Answer 1

A measure of an atoms ability to attract a shared electron pair when it is participating in a covalent bond with another atom

Question 2

What does a larger electronegativity number indicate in terms of covalent bond electron attraction?

Answer 2

A larger electronegativity number indicates a stronger attraction of electrons in a covalent bond.

Question 3

What does a smaller electronegativity number indicate in terms of covalent bond electron attraction?

Answer 3

A smaller electronegativity number indicates a weaker attraction of electrons in a covalent bond.

Question 4

What is the symbol for the number of electronegativity?

Answer 4

En

Question 5

What is the value of noble gases

Answer 5

Zero

Question 6

In a covalent bond, what happens when an electron pair is equally shared?

Answer 6

Both atoms involved share the pair of electrons.

Question 7

Which atom takes on a partial negative charge in a covalent bond?

Answer 7

The atom that attracts the pair more strongly

Question 8

What forms a polar bond

Answer 8

When an atom with lower electronegativity bonds with an atom with higher electronegativity

Question 9

What are the most common organic materials on Earth?

Answer 9

Carbohydrates.

Question 10

What elements are found in carbohydrates?

Answer 10

Carbon, Hydrogen, and Oxygen

Question 11

What ratio are the carbohydrates elements found in

Answer 11

1 : 2 : 1
C, H, O

Question 12

What three groups are carbohydrates classified into?

Answer 12

Monosaccharides, oligosaccharides, and polysaccharides

Question 13

What is the bond that links carbohydrates together?

Answer 13

Glycosidic linkage

Question 14

What are disaccharides?

Answer 14

Disaccharides are formed when two sugar molecules bond together.

Question 15

What are polysaccharides?

Answer 15

Polysaccharides are formed when several hundred to several thousand sugar molecules link together.

Question 16

What are the functions of polysaccharides?

Answer 16

Polysaccharides serve as either energy storage, like starch or glycogen, or structural support, like cellulose or chitin.

Question 17

What are lipids?

Answer 17

Lipids are a large group of hydrophobic molecules composed of carbon, hydrogen, and oxygen.

Question 18

Which four families are lipids classified?

Answer 18

Lipids are divided into four families: fats, phospholipids, steroids, and waxes.

Question 19

What is the most common energy storing molecule in living things?

Answer 19

Fat (lipids).

Question 20

What are triglycerides?

Answer 20

Triglycerides are the most common fats in plants and animals, composed of three fatty acids and one molecule of glycerol.

Question 21

Describe the structure of fatty acids.

Answer 21

Fatty acids are long hydrocarbon chains with a single carboxyl group at one end.

Question 22

How are fatty acids classified based on their bonds?

Answer 22

Saturated: all carbons having four single bonds
Unsaturated: with one or more carbon-carbon double bonds

Question 23

What is formed when glycerol reacts with a fatty acid?

Answer 23

An ester linkage is formed, along with the production of water.

Question 24

What are the components of cell membranes?

Answer 24

Cell membranes are composed of phospholipids, which have one fatty acid replaced by a phosphate group.

Question 25

Describe the polarity of the phosphate group in phospholipids.

Answer 25

The phosphate group in phospholipids is very polar and hydrophilic with respect to water.

Question 26

What is the structure of sterols?

Answer 26

Sterols contain four fused hydrocarbon rings and several different functional groups.

Question 27

What is one of the most well-known sterols?

Answer 27

Cholesterol is one of the most well-known sterols.

Question 28

What role does cholesterol play in cell membrane structure?

Answer 28

Cholesterol keeps the cell membrane strong and flexible.

Question 29

What health condition has cholesterol been linked to?

Answer 29

atherosclerosis.

Question 30

What are waxes composed of?

Answer 30

Waxes are composed of long-chain fatty acids linked to alcohols or carbon rings.

Question 31

What are waxes good for?

Answer 31

Waxes are good for waterproofing substances because they are hydrophobic.

Question 32

Can you provide an example of a wax found in plants?

Answer 32

Cutin is an example of a wax found in plants, which forms a water-resistant coating on leaves.

Question 33

What are proteins made of?

Answer 33

Proteins are made of amino acids.

Question 34

How many different R groups are there?

Answer 34

There are 20 different R groups.

Question 35

What determines the final shape of a protein?

Answer 35

The sequence of the amino acids determines the final shape of a protein.

Question 36

What are the bonds that hold amino acids together called?

Answer 36

The bonds that hold amino acids together are called peptide bonds.

Question 37

What are the two shapes of structural proteins?

Answer 37

Linear strands or sheets and spherical globular proteins.

Question 38

How many levels of protein structure are there?

Answer 38

There are four levels of protein structure.

Question 39

What is the primary structure of a protein?

Answer 39

Refers to the sequence of amino acids in a polypeptide chain.

Question 40

What is the secondary structure of a protein?

Answer 40

Involves coils and folds that occur at various points along the amino acid sequence.

Question 41

What is the tertiary structure of a protein?

Answer 41

Involves the supercoiling of a polypeptide, stabilized by side-chain interactions.

Question 42

What is the quaternary structure of a protein?

Answer 42

Represents two or more polypeptide subunits forming a functional protein.

Question 43

What are enzymes and what do they do?

Answer 43

Enzymes are protein catalysts that speed up chemical reactions without being consumed.

Question 44

How do enzymes work?

Answer 44

Enzymes work by reducing the activation energy of a chemical reaction.

Question 45

What is the substrate in enzyme reactions?

Answer 45

The specific reactant that an enzyme acts on.

Question 46

What is the active site of an enzyme?

Answer 46

The active site is the specific spot on the enzyme where the substrate binds.

Question 47

How specific are enzymes in binding to reactants?

Answer 47

Enzymes are very specific in binding to the reactants they can work with.

Question 48

What is a common characteristic of enzyme names?

Answer 48

A common characteristic is that enzyme names often end with “-ase”

Question 49

Question: How does temperature affect enzyme activity?

Answer 49

Answer: enzymes have optimal ranges to work in and can denature if taken too far out of that optimal range

Question 50

Question: What happens to enzyme catalyzed reactions as temperature increases?

Answer 50

Answer: Enzyme catalyzed reactions generally increase in speed with an increase in temperature.

Question 51

Question: What happens to enzyme structure at high temperatures?

Answer 51

Answer: At high temperatures, the protein structure of enzymes can get disrupted, resulting in denaturation and loss of enzyme function.

Question 52

Question: What is the optimal temperature for most human enzymes?

Answer 52

Answer: Most human enzymes work best at around 37 degrees Celsius.

Question 53

Question: Besides temperature, what other factors may affect enzyme activity?

Answer 53

Answer: Enzymes may require non-protein cofactors or organic coenzymes to function properly.

Question 54

Question: What are competitive inhibitors?

Answer 54

Answer: Substances that can block the enzyme's active site, preventing the normal substrate from binding.

Question 55

Question: Can competitive inhibition be overcome?

Answer 55

Answer: Competitive inhibition can be overcome by increasing the concentration of the enzyme substrate.

Question 56

Question: What are non-competitive inhibitors?

Answer 56

Answer: Non-competitive inhibitors do not affect the enzyme at its active site, and their effect cannot be overcome by adding more substrate.