energy, carbohydrates and fats Flashcards
structure of lactose
disaccharide
describe how glucose moves into cells by facilitated diffusion
carrier protein in cell surface membrane
glucose moves from high to low conc
glucose binds to carrier protein
carrier protein changes shape to move glucose across the membrane
explain how the structure of glycogen allows it to be an energy store
polymer of glucose
to provide glucose for respiration
branched/ contains 1,6 GS bonds/ has many terminal ends–> all allow for rapid hydrolysis
compact to allow large amount of glucose/ energy to be stored in a small space
insoluble so has no osmotic effect on cells
describe reaction that joins two alpha glucose molecules to form a disaccharide
condensation reaction
involving OH groups on both molecules
water is formed
structural difference between amylose and amylopectin
amylose is unbranched/ only has 1,4 GS bonds
amylopectin is branches/ has 1,4 AND 1,6 GS bonds
explain how structures of amylopectin and glycogen make them suitable for storing energy
branched so they can be rapidly hydrolysed
compact so more energy can be stored
insoluble so has no effect on osmosis
molecules are too large to diffuse across cell surface membrane
explain the effect that large quantities of a saturated lipoprotein would have on blood cholesterol levels
increase blood cholesterol
the triglyceride is saturated
the lipoprotein is an LDL
LDLs transport cholesterol
LDL binds to receptors on cell surface membranes
LDL accumulates in blood if receptors overloaded
type of reaction where two monosaccharides join
condensation reaction
glycosidic bonds are formed
two monosaccharides produced when sucrose is broken down
glucose and fructose
structure of disaccharide vs glycogen
both contain carbon, hydrogen and oxygen
both contain GS bonds
both contain glucose
glycogen contains 1,4 and 1,6 GS bonds
- disaccharides only contain one type of GS bonds
glycogen only contains glucose whereas dissacharides can contain glucose and other monosaccharides
structure of glycogen
1,4 and 1,6 glycosidic bonds
branched
how polysaccharides are broken down
hydrolysis of glycosidic bonds
describe structure of unbranched polysaccharide
made up of many monosaccharide components
joined together in a condensation by forming glycosidic bonds
only 1,4 GS bonds present
no 1,6 GS bonds
formation of glycogen from glucose
joining together in condensation reactions
forming o 1,4 and 1,6 GS bonds
why could high levels of sugar in a diet lead to obesity
energy intake higher than energy output
excess energy/ sugars can be stored as/ converted into fat
leading to weight gain, greater than overweight
obesity indicated by a BMI above 30
