biochemistry Flashcards
describe the structure of a water molecule
one atom of oxygen joined to two atoms of hydrogen by shared electrons. Because the shared negative hydrogen electrons are pulled towards the oxygen atom the other side of the hydrogen atom is left with a slight positive charge. Unshared negative electrons on the oxygen atom give it a light negative charge. This makes water a polar molecule
state properties of water that make it useful for living organisms
waters polarity makes it useful as a solvent in living organisms e.g. important substances in biological reactions are ionic. Waters polarity makes it very cohesive, waters less dense when its solid, hydrogen bonds give water a high specific heat capacity and hydrogen bonds give water a high latent heat of evaporation
why when water freezes is it less dense?
water becomes denser with lowering temperature. When near freezing point presence of hydrogen bonds means the molecule form a structure that is of a lower density hence why it floats on water.
what is the difference between an alpha glucose molecule and a beta glucose molecule?
the H and Oh are flipped to be the opposite way- alpha OH is at the bottom and in beat OH is at the top.
what is the bond between monosaccharaides?
glycosidic
what are the reactions that join monosaccharides and split disaccharides and polysaccharides?
condensation joins and hydrolysis splits
what else is produced when monosaccharieds join?
water
what is required when disaccharides and polysaccharides split?
water
what are carbohydrates made up of?
carbon, hydrogen and oxygen
what are the roles of carbohydrates?
provide energy, provide support and energy storage
give 3 examples of hexose monosaccharides
glucose, fructose and galactose
what is the difference between ribose and deoxyribose?
ribose has an OH group but deoxyribose does not- deoxyribose does not contain oxygen
what monomers is maltose made of and where is it found?
2 alpha glucose molecules, it is found in brewing sugars and breakdown of starch
what monomers is sucrose made of and where is it found?
alpha glucose and fructose, found in table sugar and plants
what monomers is lactose made of and where is it found?
alpha glucose and galactose, found in milk
what property do storage carbohydrates need?
compact
what property do structural polysaccharides need?
straight chains
what is the repeating unit of storage polysachharides?
alpha glucose
what is the significance of an OH group on the storage polysaccharide?
it starts to make the polymer coil which gives the coiled compact shape
what is the storage carbohydrate for animals?
glycogen
what is the storage carbohydrate of plants and what is it made from?
starch, made from amylose and amylopectin
give the roles of proteins
cellular structure, movement, defense transport and communication
what is the role of enzymes?
regulate chemical reactions
what elements are proteins made of?
carbon, hydrogen, oxygen, nitrogen and sulfur
what is the monomer of proteins?
amino acids
how many types of amino acids are there?
20
what can am amino acid be described as and why?
amphoteric as it has both basic and acidic group atatched to it
what is it called when two amino acids join and what is the bond that is formed called?
dipeptide- peptide bond