Module 2- Bio Molecules Flashcards
What elements are found in carbohydrates?
Carbon, Hydrogen and Oxygen
What are monosaccharides and give some examples?
Simple sugars containing 3-7 carbon atoms
glucose, galactose and fructose
Describe glucose and its function
hexose sugar (has 6 carbons in its structure)
chemical formula=C6H6O12
important source of energy in humans
during cellular respiration the energy released from glucose helps to make adenosine triphosphate (ATP)
What are isomers?
Isomers have the same molecular formula but a different arrangement of atoms. e.g alpha and beta glucose
Describe how disacchardies and polysaccharides form
Di-when 2 monosaccharides join via a condensation reaction
Poly-when more than 2 polysaccharides join together
State all 3 condensation reactions between monosaccharides
Glucose+Glucose->maltose
Glucose+Fructose->sucrose
Glucose+Galactose->lactose
What is sucrose known as?
A common table sugar
What is lactose known as?
The sugar found in milk
What are polysaccharides joined together by?
Glycosidic bonds
Examples of polysaccharides
starch, glycogen, chitin, cellulose
Structure and function of starch
-Polysaccharide formed by the condensation reaction between alpha glucose molecules
-Main energy storage material in plants
-Stored in the seeds of plants
-Is broken down into glucose by plants when they need more energy
-Acts as a source of food for animals
-Doesn’t change the water potential in a cell as it’s insoluble in water
Structure and function of amylose?
-Linear chain of alpha glucose monomers
-Helical structure
-Means their structure is compact and well suited for being a chemical energy store in plants
-1,4 glycosidic bonding
-Stabilised by hydrogen bonding between adjacent hydroxyl groups
Structure and function of amylopectin?
-alpha glucose that has 1,4 and 1,6 glycosidic bonding
-branched structure allows more glucose to be stored in the chemical energy store of the plant
-enzymes to easily access the glycosidic bonds for hydrolysis when glucose is required.
What is the structure and function of glycogen?
-energy reserve in animals
-alpha glucose
-1,4 and 1,6 glycosidic bonds
-highly branched structure allows good storage molecule as it is so compact as well as glucose being released quickly when needed
-when blood glucose levels decrease glycogen is broken down to release glucose. This is known as glycogenolysis
What is the structure and function of cellulose?
-long chain of beta glucose due to 1,4 beta glycosidic bonding
-cell walls are mostly made up of cellulose due to the strength of microfibril fibres adding rigidity and structure to the cell walls.
-cant be digested by human digestive enzymes
What is the important of water?
-major component of cells
-used as a reactant in cells
-provides structural support in cells
-keeps organisms at optimum body temp
Water is a polar molecule …
-oxygen atoms in water are slightly negatively charged (electronegative)
-hydrogen atoms in water are slightly positively charged (electropositive)
-hydrogen bonding due to uneven charge distribution
Universal solvent…
-ions and polar molecules can easily dissolve in water
-negative ends of water molecules are attracted to positively charged ions
-allows chemical reactions in organisms to happen much more quickly
Cohesion/adhesion…
-strong attraction between water molecules due to hydrogen bonding is cohesion
-polar bonds also gives water an adhesive property as it is able to cling to other polar surfaces
-Water allows for efficient transport of nutrients and waste
High surface tension…
-water molecules at the surface are more strongly attracted to each other than the air surrounding
-water striding insects are able to walk on the surfaces of water
High heat capacity…
-hc is the amount of heat 1kg of a substance must absorb to change its temp by 1degC
-hydrogen bonds let water molecules absorb a large amount of heat without changing its chemical state
-allows warm blooded animals to more evenly disperse the heat in their bodies and maintain homeostasis
-helps stabilise large bodies of water and prevents aquatic animals suffering great fluctuations in temp
Changes in density…
-the configuration of hydrogen bonds in water cause it to expand when frozen
-this causes ice to have a lower density than water
-bodies of water always freeze from the top down as the ice on the surface acts as an insulator to protect water below from freezing and allowing organisms to survive.
What are the monomers and polymers of proteins?
monomers- amino acids
polymers- polypeptides
What does the structure of an amino acid look like?
-4 atoms bonded to the central carbon
-NH2 (amine group)
-COOH (carboxylic acid group)
-H
-R (side group)
How many amino acids are there that are common in all organisms? How many of these are essential for humans and why?
20
9 because the human body can’t produce them so have to be obtained from the diet
What are the end amino acids in the polypeptide chains called?
N terminal and C terminal
Where is the peptide bond formed?
between the carboxyl group on one amino acid and the amino group of another amino acid
What is the primary structure and what is it determined by?
sequence of amino acids in a polypeptide chain and is determined by the gene encoding protein