Biology 3475A/B Chapter Notes - Chapter 45: Sesame Oil, Canola, Hemp Oil
2 May 2018
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Plants as A Human Resource Midterm 2 Notes:
Lecture 10: Human Nutrition
Why we need agriculture!
Calories: examining the label
Macronutrients: require sufficient amounts. These are lipids, proteins, carbohydrates.
Micronutrients: require smaller amounts these are vitamins, minerals.
Amount of energy supplied from food:
Calorie:
- A gram (or small) calorie (cal)is the amount of energy needed to raise 1 gram of
water by 1℃.
- A kilogram calorie (Cal) also known as dietary calorie, nutritionist's calorie,
nutritional calorie, Calorie, food calorie is approximately the amount of energy
needed to raise the temperature of 1 kg of water by 1℃.
-1000 calories (cal) is equal to 1 kilocalorie (Cal).
- 2/3 of all calories are needed to maintain body temperature in humans.
- Humans need 1200-3200 calories per day.
Fat= 9 Cals per gm.
Alcohol= 7
Carbohydrates= 4
Protein= 4
Macronutrients:
Substances that provide energy and support metabolism.
Lipids (fat and cholesterol):
- Insoluble in water
- 95% of all lipids in body are fats and oils- trigylcerides.
Carbohydrates:
- Sugars and starches.
- Mono(saccharide)- single.
-Di(saccharide)- Two singles.
- Poly(saccharide)- Multiple singles.
Lipids:
Fatty Acids:
Fatty acid: carbon chain with attached H atoms that differ in quantity between fatty
acids.
Saturated vs unsaturated:
- Refers to the amount of single bonds between carbons.
- All food contains a mixture!
Saturated: 2 hydrogen bonds on the carbons, will form solids like butter.
Unsaturated: missing H’s, contains one or more C=C double bonds. It is more difficult
for these molecules to get close together, will form more fluid, liquid things like oils.
- Can be mono unsaturated (1 C=C) or poly unsaturated (2+ C=C double bonds).
- Cis: same side.
- Trans: other side.
Examples:
Saturated fatty acids: coconut oil, palm oil. chocolate, milk, mutter, lard, pork, chicken.
Monounsaturated fatty acids: avocados, flounder, olive oil, almonds, canola oil.
Poly unsaturated fatty acids: soft margarine (most), sesame seed oil, mayo.
The Essentials (Fatty Acids):
- The body can make most fatty acids.
- Our main external source is vegetable oils.
- The three essentials are: Linoleic acid, Linolenic acid, and Arachidonic acid:
Linoleic acid: 18:2n-6/
- Omega-6 Fatty acid.
- Colourless liquid at room temperature.
- 18-carbon chain and 2 cis double bonds, the first is located at the sixth carbon
from the omega end (the omega end is opposite the carboxylic acid group, it is
the methyl end).
- Is readily available in our diets, even if you don’t use the following oils, they are
in a lot of processed foods and used in food preparation.
Ex. Sunflower oil (68%), hemp oil, peanut oil, canola oil, egg yolk (16%), butter
(2%).
Linolenic acid: All-cis-9, 12, 15- octadecatienoic acid.
- In many vegetable oils.
- Seed oils are the richest source; rapeseed, soy bean, walnut, flaxseed etc.
Arachidonic acid:
- 20 carbon chain and 2 cis bonds.
- Needed in membranes.
- Abundant in brain and muscles.
- Involved in cellular signaling and inflammatory
Hydrogenation:
Manufacturers can’t use oils for everything; need to change them for different purposes.
- Done to obtain desired traits: texture, dispersion, shelf life.
- Unsaturated oils often hydrogenated.
- Oils reacted with hydrogen gas at high temp and pressure become saturated.
- Process used to give pliability
- Trans fats formed.
Ex. We can take an oil, like plant oil and make margarine- a solid.
Fatty acid summary:
Triglyceride: used for energy storage ex. Animal fat, vegetable oil and insulation ex.
Subcutaneous fat. This is a glycerol + a fatty acid.
Steroid: Structure ex. Cholesterol in membranes, hormonal regulation ex. Cortisol,
estrogen, testosterone.
Phospholipids: structure ex. Phosphatidylcholine in cell membranes.
Cholesterol:
- Sub category of lipids (in the steroid category)
- Vital component of membranes- synthesis of some hormones.
- Synthesized in liver or absorbed in intestine.
- Not found in plant sources (unsaturated).
- Insoluble in blood.
- Helps things become malleable; more viscous and less viscous to adjust to
temperature.
- Wheat will be able to adjust to temperature (their plasma membrane has
cholesterol to keep in from becoming solid in the winter.
There is high and low density lipoproteins.
LDL: the bad cholesterol- forms can be taken up by cells lining arteries which can casue
heart attack and stroke.
HDL: the good cholesterol- helps manage and reduce overall levels.
Carbohydrates:
Glucose:
- Basic building block of carbohydrates.
- Form transported in blood.
- Needed for cellular respiration.
Monosaccharides:
- Basic building blocks.
- Glucose, fructose and galactose.
Disaccharides:
Sucrose: Glucose and fructose combined.
Ex. Table sugar, from sugar cane and sugar beet.
Lactose: Glucose and galactose combined.
Polysaccharides:
- Complex sugars, hundreds or thousands of monosaccharides joined together.
Starch: storage form of glucose in plants. Ex. Wheat, rice, potato etc.
- Linear chains, no branches
Glycogen: storage from of glucose in animals. One days worth stored in liver and
the rest converted to fat.
Why would plants want to store sugar as starch? It prevents osmotic problems as
it is insoluble.
Fibre: cellulose, lignin, hemicellulouse, and pectin.
- Not digested, provides bulk.
- Grains, legumes, fruits and vegetables.
- Soluble: what makes wet oatmeal sticky.
- Insoluble: sponge-like version in bran and in fruit and vegetable skins which
absorb water, prevent constipation, and may lower colorectal cancer risk.
Document Summary
Plants as a human resource midterm 2 notes: Micronutrients: require smaller amounts these are vitamins, minerals. A gram (or small) calorie (cal)is the amount of energy needed to raise 1 gram of water by 1 . A kilogram calorie (cal) also known as dietary calorie, nutritionist"s calorie, nutritional calorie, calorie, food calorie is approximately the amount of energy needed to raise the temperature of 1 kg of water by 1 . 1000 calories (cal) is equal to 1 kilocalorie (cal). 2/3 of all calories are needed to maintain body temperature in humans. 95% of all lipids in body are fats and oils- trigylcerides. Fatty acid: carbon chain with attached h atoms that differ in quantity between fatty acids. Refers to the amount of single bonds between carbons. Saturated: 2 hydrogen bonds on the carbons, will form solids like butter. Unsaturated: missing h"s, contains one or more c=c double bonds.
