Carbohydrates Flashcards
What are the3 types of carbohydrates?
Monosaccharides = monomers, polysaccharides and disaccharides
Name some monosaccharides
Glucose and fructose and galactose
Name some polysaccharides
Starch glycogen chitin cellulose
Name some disaccharides / dimer
Sucrose lactose maltose
What elements are in carbohydrates
Carbon, hydrogen oxygen
Functions of carbohydrates
Instant energy source, because respiration by glucose and transportables or storage forms of energy and structural materials glycoproteins in cell membranes
3,5,6 carbon molecules = sugar name?
Triose,pentose, hexose
General formula carbohydrates
(CH2O)n
Why is it good that glucose is a polar molecule
Very soluble and transported in blood stream
What are the 2 types of glucose and how are they different
Alpha and beta glucose. They are isomers (same chemical formula but different arrangement in space). In alpha, OH group is below carbon 1 but above carbon 1 in beta
How is water a polar molecule
Oxygen atom has slightly negative charge because it attracts electrons and hydrogen is slightly positive because the electrons move away.
Define polar molecule
Slightly uneven . distribution of charge across different parts of a molecule leading to no overall charge
Which monosaccharides make up lactose sucrose and maltose
Lactose = galactose + glucose
Sucrose= glucose + fructose
Maltose= glucose + glucose
What happens in a condensation reaction for carbs
Larger molecules form, new covalent glycosidic bond forms and water molecule is removed from smaller molecules being combined
What happens in hydrolysis reaction for carbs
Smaller molecules formed, covalent bond broken, water molecule added from large molecules being broken down
What are polysaccharides and why are they ideal storage molecules (starch + glycogen)
Polymers made from glucose molecules and ideal because they are compact as they are coiled and branched and helical shaped /form spirals so easy to add/remove glucose to release/store energyand insoluble so don’t affect the osmotic potential and its easy to add and remove glucose molecules because branched ends means lots of glucose molecules released at once and have high energy content 17kJ/g and are large molecules so can’t leave cell
Starch → purpose: energy source for plants
Polymers amylopectin and amylose
Amylose is a straight coiled chain of alpha glucose molecules joined by 1-4 glycosidic bonds and amylopectin is a branched and coiled chain with 1-4 bonds and the branches form between carbons 1 and 6 of adjacent monomers
Glycogen
The energy store for animals in liver + muscle cells - polymer of alpha glucose - with 1,4 glycosidic bonds creating coiled chain (more coiled then and amylopectin) due to sidechains attached by 1,6 glycosidic bonds so more compact than starch and stored as granules in liver and muscle cells
Cellulose
Structural support in plant cell walls and prevent from bursting when turgid - long straight chains of beta glucose with 1,4 glycosidic bonds + every other glucose molecule rotated 180° relative to next molecules H bonds form between OH groups of long parallel multiple chains like layers → cross-linking = microfibril = very strong
Chitin
Cell walls for fungi and exoskeletons of insects ( contains nitrogen) with beta glucose + same structure as cellulose but OH group on carbon 2 replaced with acetyl amide side chain containing nitrogen
Definition of disaccharide / how are they formed
Two monosaccharides joined I bonded together by a condensation reaction with glycosidic bond joining two hexose units
Monomer for chitin
B glucose with acetyl amide side chain
Structural formula for monosaccharides
Either straight chain or rings
What type of bond is important in helping maintain shape of biological molecules
Hydrogen bonding
