Topic 1A- Biological Molecules (Carbohydrates) Flashcards
What is covalent bonding?
What does covalent bonding do to atoms?
What is formed in covalent bonding?
What is ionic bonding and give an example?
What are ionic bonds compared to covalent bonds?
What is hydrogen bonding and give an example?
What is this process also known as?
What is a molar solution?
What is the full definition of a mole?
Where atoms share a pair of electrons in their outer shells
It increases their stability
In covalent bonding a more stable compound called a molecule is formed
Ions with opposite charges attract one another (eg Na+ and Cl-
Ionic bonds are weaker than covalent bonds
Where electrons concentrate in one area and creates a polarity and in turn this attracts molecules in a weak bond (eg water)
Hydrogenisation
A solution that contains one mole of solute in each litre of solution
A mole is the molecular mass (molecular weight) expressed as grams (=one gram of molecular mass).
What are most carbohydrates, proteins and nucleic acids?
What are most biological polymers formed by?
What does a condensation reaction form?
How can polymers be broken down by?
What three elements are carbohydrates made from?
What is the function of carbohydrates?
What do plant cell walls depend on?
What are the three types of carbohydrates?
Polymers
Condensation reactions
A chemical bond between monomers, releasing a molecule of water
In a hydrolysis reaction
Carbon, hydrogen and oxygen
They store energy in plants and animals
The structural role of some carbohydrates
Monosaccharide’s, disaccharides and polysaccharides.
What are monosaccharide’s?
What do monosaccharide’s have concerning carbon and oxygen atoms?
What is the general formula of monosaccharide’s?
What does the n stand for and what is this between?
What type of solids are monosaccharide’s?
What is a monosaccharide called with 3, 5 and 6 carbon atoms?
What is the bond formed called from the formation of a disaccharide?
Why does a condensation reaction occur?
What happens to disaccharide’s to form monosaccharide’s?
What happens in this reaction as a result?
The simplest single sugars
They have the same number of carbon as of oxygen atoms
(CH2O)n
Number of carbon atoms and is between 3 and 7
White crystalline solids
Triose, pentose and hexose
Glycosidic bond
Occurs to join the two monosaccharides
Disaccharide’s hydrolyse to form monosaccharide’s
The disaccharides gain a H2O molecule.
What are the two types of glucose?
What are both of these molecules and describe?
What happens to the OH group in alpha glucose?
What happens to the OH group in beta glucose?
What are the main two monosaccharide’s?
What is the equation for the formation of sucrose?
What is the equation for the formation of lactose?
What is the equation for the formation of maltose?
How are disaccharide’s formed and by what reaction?
In what two ways can a disaccharide be made?
What determines which disaccharide is formed?
Alpha and beta glucose
Alpha and beta glucose are isomers of each other (ie they have the same chemical formula but different chemical structures)
The OH group is attached below carbon 1 in alpha glucose
The OH group is attached above carbon 1 in beta glucose
Glucose and Fructose
Glucose + Fructose —> Sucrose
Galactose + Glucose —> Lactose
Glucose + Glucose —> Maltose
When two monosaccharide units join forming a glycosidic bond, by a condensation reaction
Can be made from two of the same monosaccharide molecules or from two different ones
The combination of monosaccharide’s.
What are the three main disaccharides?
What is the definition of polysaccharides and what are they known as?
What is the full definition of polymerisation?
What are the monomers of polysaccharides?
What is the monomer and glycosidic bond (attraction between certain carbon atoms in the structure) for the following polysaccharides:
Starch
Glycogen
Cellulose
What does a glycosidic bond of 1-4 for example mean?
Starch, cellulose and glycogen
Large complex molecules known as polymers
The process of bonding many monomers by condensation reactions to form one large molecule
Monomers are the individual monosaccharide’s which join to form the polysaccharides
Monomer of alpha glucose and glycosidic bond of 1-4
Monomer of alpha glucose and glycosidic bond of 1-4 and 1-6
Monomer of beta glucose and glycosidic bond of 1-4
Glycosidic bond of 1-4 means carbon 1 is attracted to carbon 4.
What is the simplified form of alpha glucose?
What is the simplified form of beta glucose?
H-1C=O Simplified Form of Alpha Glucose
/
H-2C-OH
/
HO-3C-H
/
H-4C-OH
/
H-5C-OH
/
H-6C-OH
/
H
O=1C-H Simplified Form of Beta Glucose.
/
HO-2C-H
/
H-3C-OH
/
HO-4C-H
/
HO-5C-H
/
HO-6C-H
/
H
What is the structure of starch and how does this help it?
What is starch and why?
What does this mean it doesn’t affect?
What does this therefore mean concerning use in plants?
What is amylose and how’s this useful in starch?
What is amylopectin and how’s this useful in starch?
How is glycogen used in animal cells?
What is glycogen?
What are the two properties of glycogen and how is this helpful in animal cells?
What is the polymer in cellulose?
What are the physical appearances of cellulose?
What chains does cellulose form and what intern does this form?
What are these bonds like?
How does being fibrous help cellulose in plants?
The alpha-helical structure of starch makes it good for storage (it’s compact)
Starch is insoluble due to its structure
So doesn’t affect water potential
It’s therefore the main plant storage of glucose/sugar, as it doesn’t affect water movement
Unbranched so good for storage and compact
Branched and so can be hydrolysed easily and quickly
Animal cells store excess glucose as glycogen
An alpha glucose
- Highly branched (more than amylopectin) for quick energy release
- Very compact and therefore good to store
Polymer of beta-glucose
Long and unbranched, with inverted monomers
Forms chains which run parallel with hydrogen bonds between the chains to form microfibrils
Microfibrils are strong
Cellulose is structurally important in plant cell walls.
What will all monosaccharide’s and most disaccharides do?
What disaccharide does this exclude?
What are these compounds called?
What do the following colours mean if produced in the reducing sugar test method:
Original pale blue
Green precipitate
Brown or red precipitate
Why is sucrose called a non-reducing sugar?
What is sucrose the only sugar to do?
What is the test for starch and what is the colour change for a positive result?
Reduce copper (II) sulphate, producing a precipitate of copper (I) oxide on heating
Except sucrose
Reducing sugars
Original pale blue colour means no reducing sugar
A green precipitate means relatively little sugar
A brown or red precipitate means progressively more sugar
Because it doesn’t reduce copper sulphate, as the groups needed for the reaction form the bonds between the monosaccharide’s
Sucrose is the only sugar that will give a negative Benedict’s test before hydrolysis and a positive test afterwards
Iodine (positive result is a colour change from browny/orange to dark blue/black colour).
