| draw the formation of a disaccharide | diagram |
| What are some examples of monosaccharides (one sugar unit) | glucose, galactose and fructose
usually sweet tasting and is an immediate energy source for cells |
| What are some examples of disaccharides (2 sugar units) | lactose, sucrose and maltose small enough to be water soluble, transport form of carbohydrates |
| What are some examples of polysaccharides? | cellulose glycogen and starch used for energy storage or cell structure |
| what does the type of polymer formed depend upon? | monosaccharide subunits
bonding arrangement between them |
| Which polymers can be found in plants? | cellulose and starch |
| which polymers can be found in animals? | glycogen |
| What is cellulose? (3 + 2 examples) | polysaccharide (structural)
found in the cell wall of plants
linear molecule made of beta glucose in a 1-4 arrangement
b glucose is indigestable to most animals as they lack the enzyme to break it down
eg: cows (ruminants) digest cellulose because of bacteria in a specialized stomach
eg: rabbits (caecotrophs) will reingest specialized feces that have digested cellulose |
| What is starch (mention amylose) | polysaccharide (energy storage) in plants
a glucose in a 1-4 arrangement
found as amylose or amylopectin
Amylose is a linear (helical) molecule
Amylopectin is branched with 1-6 linkages added
amylose is harder to digest and is less soluble = but it takes up less space so it is a better storage form |
| What is glycogen? (3) | energy storage polysaccharide in the liver
made of a glucose linked with 1-4 and 1-6 (branching)
similiar to amylopectin because of branching |
| What are fatty acids? | long hydrocarbon chains in certain lipids (triglycerides and phospholipids)
hydrocarbon chain LENGTH can differ and number of DOUBLE BONDS |
| What are saturated fatty acids? | they have no double bonds (max number of H atoms)
linear
from animal sources (fat)
solid at room temp |
| What are unsaturated fatty acids? (level up) | they HAVE DOUBLE BONDS
monosaturated = 1 double bond
polysaturated = more than1 double bond
bent
from plant sources (pols)
liquid at room temp |
| What are the two different structures of unsaturated fatty acids? | cis isomers
trans isomers |
| What are cis isomers? | hydrogen atoms attach to the carbon double bond are on the same side |
| What are trans isomers? | hydrogen atoms attached to the carbon double bond are on different sides |
| Where do TRANS fatty acids come from? (transgender) | don't happen naturally but are produced by an INDUSTRIAL PROCESS called hydrogenation
linear even though they are unsaturated
solid at room temp |
| What are triglycerides? | long term energy storage
animals store them as fats (solids)
plants store them as oils (liquids)
formed when condensation reactions happen between 1 GLYCEROL AND 3 FATTY ACIDS |
| Explain the formation of a triglyceride | condensation reaction between 1 glycerol and 3 fatty acids
hydroxyl group of glycerol joins with the carboxyl group of the fatty acids
= ester linkage
produces 3 molecules of water
can be saturated or unsaturated = depends on the composition of teh fatty acid chain |
| Which fats increase cholesterol levels in the bloodstream? | saturated and trans fats |
| Which fats lower cholesterol levels? | cis unsaturated fats |
| Example of unsaturated , saturated and trans fat | almonds
beef
cookies |
| How is fat and cholesterol transported and why are they transported this way? | because they can't dissolve in blood they are packaged with proteins = lipoproteins for transport |
| What do low density lipoproteins do (LDLs)> | carries cholesterol form the liver to the body
= raises cholesterol levels - bad |
| what do high density lipoproteins do (HDL)? | carry excess cholesterol back to the liver for disposal
= lowers cholesterol levels |
| How does a high intake of the different types of fat affect cholesterol levels? | Saturated fats = increase LDL levels = raises blood cholesterol
Trans fats = increase LDL levels AND decreases HDL levels = raises blood cholesterol ALOT
Unsaturated (cis) fats = increase HDL levels = lowers blood cholesterol |
| What does high cholesterol lead to? | hardening and narrowing of arteries (artherosclerosis)
high levels of LDL = LDL particles forms deposits in the walls
fat accumulation = development of plaque which reduces blood flow
Coronary Arteries become blocked = CHD which causes heart attacks and strokes |
| What are the two main health claims about lipids in diet? | diets with too much saturated and trans fats = increase in CHD risk
Diets with a lot of mono unsat and poly unsat (cis) = decrease CHD risk |
| What is some evidence that supports that saturated and trans fats increase the risk of CHD? | positive correlation with intake of sat fats and CHD in people
BUT some populations don't fit this ( maasai tribe have a fat rich diet but low rates of CHD)
Intervention studies show that lowering sat fat intake reduces factors = CHD development (BP)
BUT study's validity depends on sample size and study duration |
| What is some evidence that goes against that saturated and trans fats increase the risk of CHD? | amount of sat and rans fats in western diets have reduces over last 50 years but CHD cases increases
BUT increased carbs causes detrimental health effects as well (eg: diabetes)
ALSO CHD depends on other factors as well like exercise |
| Differences in energy storages of carbs and lipids (5) | Storage
CARB: short term energy storage
LIPID: long term energy storage
Osmotic effect
CARB: more effect on cell
LIPID: less effect on cell
Digestion
CARB: easily digested
LIPID: harder to digest
ATP Yield:
CARB: stores half as much ATP per gram
LIPID: stores 2x as muc ATP per gram
Solubility
CARB: water soluble as monomers - easy to transport
LIPID: not water soluble (hydrophobic) - difficult to transport |
| How is ATP made? | energy made with cell respiration and can be used in metabolism |
| What is BMI? | body mass index measures relative mass based on weight and height to see potential weight problems in sedentary adults |
| How is BMI calculated? | BMI = mass in kg / (height in m)2 squared |
| Who are the BMI not accurate for? | pregnant women
professional athletes as they have unrepresentative muscle/ fat ratios
used with other measurements SHOULD NOT BE used as a diagnostic tool |
