C1: The Chemical Basis Of Life Flashcards
What is electronegativity?
A measure of an atoms ability to attract a shared electron pair when it is participating in a covalent bond with another atom
What does a larger electronegativity number indicate in terms of covalent bond electron attraction?
A larger electronegativity number indicates a stronger attraction of electrons in a covalent bond.
What does a smaller electronegativity number indicate in terms of covalent bond electron attraction?
A smaller electronegativity number indicates a weaker attraction of electrons in a covalent bond.
What is the symbol for the number of electronegativity?
En
What is the value of noble gases
Zero
In a covalent bond, what happens when an electron pair is equally shared?
Both atoms involved share the pair of electrons.
Which atom takes on a partial negative charge in a covalent bond?
The atom that attracts the pair more strongly
What forms a polar bond
When an atom with lower electronegativity bonds with an atom with higher electronegativity
What are the most common organic materials on Earth?
Carbohydrates.
What elements are found in carbohydrates?
Carbon, Hydrogen, and Oxygen
What ratio are the carbohydrates elements found in
1 : 2 : 1
C, H, O
What three groups are carbohydrates classified into?
Monosaccharides, oligosaccharides, and polysaccharides
What is the bond that links carbohydrates together?
Glycosidic linkage
What are disaccharides?
Disaccharides are formed when two sugar molecules bond together.
What are polysaccharides?
Polysaccharides are formed when several hundred to several thousand sugar molecules link together.
What are the functions of polysaccharides?
Polysaccharides serve as either energy storage, like starch or glycogen, or structural support, like cellulose or chitin.
What are lipids?
Lipids are a large group of hydrophobic molecules composed of carbon, hydrogen, and oxygen.
Which four families are lipids classified?
Lipids are divided into four families: fats, phospholipids, steroids, and waxes.
What is the most common energy storing molecule in living things?
Fat (lipids).
What are triglycerides?
Triglycerides are the most common fats in plants and animals, composed of three fatty acids and one molecule of glycerol.
Describe the structure of fatty acids.
Fatty acids are long hydrocarbon chains with a single carboxyl group at one end.
How are fatty acids classified based on their bonds?
Saturated: all carbons having four single bonds
Unsaturated: with one or more carbon-carbon double bonds
What is formed when glycerol reacts with a fatty acid?
An ester linkage is formed, along with the production of water.
What are the components of cell membranes?
Cell membranes are composed of phospholipids, which have one fatty acid replaced by a phosphate group.
Describe the polarity of the phosphate group in phospholipids.
The phosphate group in phospholipids is very polar and hydrophilic with respect to water.
What is the structure of sterols?
Sterols contain four fused hydrocarbon rings and several different functional groups.
What is one of the most well-known sterols?
Cholesterol is one of the most well-known sterols.
What role does cholesterol play in cell membrane structure?
Cholesterol keeps the cell membrane strong and flexible.
What health condition has cholesterol been linked to?
atherosclerosis.
What are waxes composed of?
Waxes are composed of long-chain fatty acids linked to alcohols or carbon rings.
What are waxes good for?
Waxes are good for waterproofing substances because they are hydrophobic.
Can you provide an example of a wax found in plants?
Cutin is an example of a wax found in plants, which forms a water-resistant coating on leaves.
What are proteins made of?
Proteins are made of amino acids.
How many different R groups are there?
There are 20 different R groups.
What determines the final shape of a protein?
The sequence of the amino acids determines the final shape of a protein.
What are the bonds that hold amino acids together called?
The bonds that hold amino acids together are called peptide bonds.
What are the two shapes of structural proteins?
Linear strands or sheets and spherical globular proteins.
How many levels of protein structure are there?
There are four levels of protein structure.
What is the primary structure of a protein?
Refers to the sequence of amino acids in a polypeptide chain.
What is the secondary structure of a protein?
Involves coils and folds that occur at various points along the amino acid sequence.
What is the tertiary structure of a protein?
Involves the supercoiling of a polypeptide, stabilized by side-chain interactions.
What is the quaternary structure of a protein?
Represents two or more polypeptide subunits forming a functional protein.
What are enzymes and what do they do?
Enzymes are protein catalysts that speed up chemical reactions without being consumed.
How do enzymes work?
Enzymes work by reducing the activation energy of a chemical reaction.
What is the substrate in enzyme reactions?
The specific reactant that an enzyme acts on.
What is the active site of an enzyme?
The active site is the specific spot on the enzyme where the substrate binds.
How specific are enzymes in binding to reactants?
Enzymes are very specific in binding to the reactants they can work with.
What is a common characteristic of enzyme names?
A common characteristic is that enzyme names often end with “-ase”
Question: How does temperature affect enzyme activity?
Answer: enzymes have optimal ranges to work in and can denature if taken too far out of that optimal range
Question: What happens to enzyme catalyzed reactions as temperature increases?
Answer: Enzyme catalyzed reactions generally increase in speed with an increase in temperature.
Question: What happens to enzyme structure at high temperatures?
Answer: At high temperatures, the protein structure of enzymes can get disrupted, resulting in denaturation and loss of enzyme function.
Question: What is the optimal temperature for most human enzymes?
Answer: Most human enzymes work best at around 37 degrees Celsius.
Question: Besides temperature, what other factors may affect enzyme activity?
Answer: Enzymes may require non-protein cofactors or organic coenzymes to function properly.
Question: What are competitive inhibitors?
Answer: Substances that can block the enzyme’s active site, preventing the normal substrate from binding.
Question: Can competitive inhibition be overcome?
Answer: Competitive inhibition can be overcome by increasing the concentration of the enzyme substrate.
Question: What are non-competitive inhibitors?
Answer: Non-competitive inhibitors do not affect the enzyme at its active site, and their effect cannot be overcome by adding more substrate.
