B1.1.1 - B1.1.4 Flashcards
When does a covalent bond form?
A covalent bond forms when a pair of electrons are shared between two atoms.
Why are electrons shared between atoms?
Electrons are shared between atoms to generate strong bonds within compounds.
What is carbon present in?
-Lipids
-Proteins
-Nucleic acids
-Carbohydrates
How many electrons does carbon have in its outer shell? What does this mean?
Carbon has 4 valence electrons, meaning it can form 4 covalent bonds.
What can carbon bond to?
Carbon can bond to other carbon atoms, or other atoms such as hydrogen, nitrogen or oxygen.
What is an example of carbon atoms arranging themselves to form molecules with long branched chains?
Glycogen.
What is an example of carbon atoms arranging themselves to form long straight chain molecules?
Cellulose.
What is an example of carbon atoms arranging themselves to form molecules containing cyclic single rings?
The pyrimidines (thymine, uracil and cytosine).
What is an example of carbon atoms arranging themselves to form molecules with multiple rings?
Starches and purines (adenine and guanine).
What allows carbon to form varied carbon compounds with different shapes and hence, different biological properties?
Carbon produces a tetrahedral structure allowing it to form varied carbon compounds which have different 3-D shapes and hence, different biological properties.
How many bonds can carbon atoms form and what combination?
Carbon atoms can form up to four single covalent bonds or a combination of double and single bonds.
What functional groups can carbon atoms form part of that give organic compounds their individual properties?
-Hydroxyl groups
-Carboxyl groups
-Amino groups
-Phosphate groups
How can carbon compounds be large molecules?
Carbon compounds can be large molecules by being made from many small, repeating subunits.
What are monomers?
Monomers are the smaller units from which larger molecules are made.
What are polymers?
Polymers are molecules made from a large number of monomers joined together in a chain.
What is the process by which monomers join to form polymers?
Polymerisation.
What are macromolecules?
Macromolecules are very large molecules.
Why can polymers be macromolecules but not all macromolecules are polymers?
Polymers must consist of many repeating subunits.
How are macromolecules formed?
Macromolecules are formed during condensation reactions.
What is a condensation reaction?
A condensation reaction occurs when molecules combine together, forming covalent bonds and resulting in polymers (polymerisation) or macromolecules.
-Water is removed as part of the reaction.
What are examples of condensation reaction?
-Polysaccharides
-Polypeptides
-Nucleic acids
How are polysaccharides formed?
Polysaccharides are formed when two hydroxyl groups on different monosaccharides interact to form a strong covalent bond called a glycosidic bond.
How are polypeptides formed?
Polypeptides are formed by condensation reactions. Two amino acid monomers interact to form a strong covalent bond called a peptide bond.
How are nucleic acids formed?
Separate nucleotides are joined together via condensation reactions to form a phosphodiester bond.
Between what do the condensation reactions occur to form nucleic acids?
The condensation reactions occur between the phosphate group of one nucleotide and the pentose sugar of the next nucleotide.
Why is it called a phosphodiester bond?
Because it consists of a phosphate group and two ester bonds.
What happens to macromolecules in digestion?
In digestion, macromolecules are broken down into their monomers.
What allows macromolecules to be broken down into their monomers?
A hydrolysis reaction.
What is a hydrolysis reaction?
The hydrolysis of macromolecules is when covalent bonds are broken when water is added. The -O and -OH from water are used to form the functional groups of the products.
What is the difference between a condensation and hydrolysis reaction?
A condensation reaction is when water is removed whereas a hydrolysis reaction is when water is added.
What are examples of hydrolysis reactions?
-hydrolysis of glycosidic bonds in poly- or disaccharides to produce monosaccharides.
-hydrolysis of peptide bonds in polypeptides to produce amino acids.
-hydrolysis of ester bonds in triglycerides to produce three fatty acids and glycerol.
What are monosaccharides?
Monosaccharides are the monomers of carbohydrates.
How to form a disaccharide?
By joining two monosaccharides.
How to form a polysaccharide?
By joining many monosaccharides.
How can monosaccharides join together and what is the new chemical bond between two monosaccharides called?
They can join together by condensation reactions. The new chemical bond that forms is known as a glycosidic bond.
What are the properties of monosaccharides?
-Colourless crystalline molecules.
-Soluble in water.
What is the most common monosaccharide?
Glucose.
How does glucose aid in the production of ATP?
It is the main substrate used in respiration, releasing energy for the production of ATP.
During what is glucose produced?
Photosynthesis.
In what two structurally different forms does glucose exist as?
-Alpha glucose
-Beta glucose
What does the structural variety between alpha and beta glucose result in?
It results in different functions between carbohydrates.
What are the properties of glucose?
-Stable structure due to the presence of covalent bonds which are strong and hard to break
-Soluble in water due to its polar nature
-Easily transportable due to its water solubility
-A source of chemical energy when its covalent bonds are broken
-Oxidation of glucose provides large amounts of energy.
