1.1 - chemical elements and biological compounds Flashcards
what are the 4 living things biological molecules are made up of?
carbohydrates, lipids, proteins and nucleic acids
what can carbohydrates, lipids, proteins and nucleic acids been named as? what are their general formulas?
macromolecules
CH2O
what is meant by a monosaccharide?
a single unit - building blocks of life, sugar molecules, determined by C atoms
what would we called a monosaccharide with 3 C atoms? 5 C atoms? 6 C atoms?
triose sugar
pentose sugar
hexose sugar
what is the most common hexose sugar?
alpha glucose
how would you draw a-glucose?
!
what formula do hexose sugars like a-glucose have?
C6 H12 O6
what is the difference between a-glucose and beta glucose?
a - glucose = H at top OH on bottom
beta glucose = OH at top H on bottom
what two isomers does glucose have?
alpha and beta glucose
what monosaccharides make up the disaccharide sucrose?
frutose and glucose
what monosaccharides make up the disaccharide maltose?
a-glucose and a-glucose
what monosaccharides make up the disaccharide lactose?
galactose and a-glucose
what is a polysaccharide?
3 or more sugars joined together e.g. starch
how is a monosaccharide turned to a disaccharide? what reaction? what bond is formed?
condensation reaction forms a glycosidic bond -water is made and H and OH comes off
how is a disaccharide turned to a monosaccharide? what reaction?
hydrolysis - water splits up
glucose is stored as…in…?
starch in plants
is starch insoluble what does this mean?
yes. cannot be dissolved - prevents diffusion
what is starch made up of?
amylose and amylopectin
describe amylose?
formed by condensation reaction between 3+ a-glucose, 1,4 links - coiled springs are formed
describe amylosepectin?
formed by condensation reaction but with beta glucose but 1,6 links and a branched structure
what is the test for starch?
iodine solution, positive = blue/black
negative=brown/yellow
what does polysaccharide chitin make up?
makes up fungal walls and exoskeleton of insects
what does chitin contain?
nitrogen - 1 OH is replaced with N -acetyl group
how is the polysaccharide structured?
2 beta-glucose, 1,4 bonds and flips 180 degrees so the hydrogen can be formed
what does the polysaccharide glycogen do?
stores glucose in animals
how is glycogen?
more branches - extremely compact so its good for respiration. 1,4 and 1,6 bonds
what is meant by a reducing sugar. give 3 examples.
able to give away an electron - glucose, galactose fructose , maltose and lactose
what is the test for reducing sugars?
add Benedict substance and heat
positive = red
negative =blue/green
what is an example of a non-reducing sugar?
sucrose
how do you test for non-reducing sugars?
add hcl acid, neutralise with hydrogen carbonates - repeat Benedict’s test and heat
how would you test for protein?
biuret solution
positive = purple
negative= no colour change
how do you test for lips (fats and oils)?
mixed with ethanol and shake
postive = cloudy white emulsion
