Fats. Flashcards
What states are fats and oils found at room temperature?
Fats are solid at room temperature and oils are liquid at room temperature.
What are the 9 functions of fats?
- For energy.
- For body warmth.
- Surrounds and protects certain vital organs e.g. kidney.
- Forms an insulating layer (adipose tissue) beneath the skin to preserve body heat and protect the skeleton and organs.
- Forms part of the cell membranes, especially in the brain.
- Provides a source for fat-soluble vitamins A, D, E and K.
- Increases calories without adding bulk.
- Provides texture and flavor.
- Foods containing fat provide a feeling of fullness (satiety).
The chemical elements that are found in fats are:
Carbon, hydrogen, and oxygen.
What do the three chemical elements found in fats make up to form fat molecules?
These elements make up molecules of glycerol and fatty acids, which combine to form fat molecules.
What two subsections can fats fall under depending on how the carbon and hydrogen atoms are arranged?
They are either saturated or unsaturated depending on how the carbon and hydrogen atoms are arranged.
Answer the following objectives on saturated fats regarding their:
- the amount of hydrogen atoms.
- joined by what type of bond.
- state at room temperature.
- plant/animal sources.
- contains cholesterol or not.
- They contain the maximum amount of hydrogen atoms and cannot accept any more.
- They are joined by a single bond.
- They are solid at room temperature e.g. butter, lard, animal fat, and coconut oil.
- Usually from animal sources.
- Contains cholesterol.
Answer the following objectives on unsaturated fats regarding their:
- joined by what type of bond.
- are carbon and hydrogen atoms complete?
- acceptance of hydrogen atoms.
- plant/animal sources.
- Some carbon atoms are joined by a double bond.
- Some carbon atoms have hydrogen missing.
- Carbon atoms can accept hydrogen atoms.
- Usually from plant sources.
Answer the following objectives on mono-unsaturated fats regarding their:
- what type of bond.
- acceptance of hydrogen.
- sources.
- state at room temperature.
- Have only one double bond e.g. oleic acid.
- Molecule can accept more hydrogen.
- Found in most animal and plant fats and oil, especially olive oil.
- Liquid at room temperature.
Answer the following objectives on poly-unsaturated fats regarding their:
- acceptance of hydrogen bonds.
- the type of bond.
- state at room temperature.
- Can take more hydrogen bonds.
- Has more than one double bond.
- Liquid at room temperature e.g. sunflower oil, canola oil.
How is fat present in food?
Fat is present in food as either visible or invisible fat.
Give three examples of visible fats:
- Fat on meat.
- Butter, margarine, lard, suet.
- Cooking fats and oils.
Give five examples of invisible fats:
- Lean meat (marbling).
- Egg yolk.
- Flesh on oily fish.
- Nuts, seeds, fruits.
- Prepared foods e.g. pastry, cakes, biscuits, fried foods e.g. fritters, croquettes.
NOTE - Draw table of animal and plant sources on page 7.
Excess fat is stored as fat under the skin as adipose tissue and can cause the following:
- Hypertension.
- Obesity.
- Cholesterol.
What is hypertension?
Is when blood pressure is abnormally high and causes the heart to work harder and then puts pressure on blood vessels and may damage arteries.
What does obesity cause?
Which can cause breathlessness, lethargy, lack of self-esteem, and problems during surgery.
What is cholesterol.?
Excess saturated fat is deposited in the blood vessels, which then narrows the blood vessels and cause CHD.
What is the effect of frying food?
Fried foods absorb fat and increase the energy value of the food.
Are fat-soluble vitamins affected by heat?
Fat-soluble vitamins are not affected by heat.
What are the four effects of heat on fats?
- When heated, solid fats melt and become liquid.
- As heating continues, the oil becomes thinner and begins to bubble.
- At very high temperatures, the fat molecules begin to decompose into glycerol and fatty acids.
- A blue haze can be seen, then smoke, then the fat ignites and burns rapidly.
Unsaturated fatty acids may either ___ or _____. ____ fats are good for us and _____ fats are bad for us.
Unsaturated fatty acids may either cis or trans. Cis fats are good for us and trans fats are bad for us.
These are fatty acids that the body needs but cannot make. Give two fatty acids which resonate with this statement.
Linoleic acid and Linolenic acid.
Why do babies/foetus need linoleic acid and linolenic acid?
It is needed for brain development in babies/foetus.
What does linoleic acid and linolenic acid do to lower and prevent?
It helps lower cholesterol and prevents blood clots.
How do humans make linoleic acid and linolenic acid and oily fish?
Humans make it in breast milk e.g. omega 3 and omega 6 from oily fish e.g. salmon/mackerel.
Fat refers to both ___ and ____. Sometimes the word ‘____’ is used to describe fats.
Fat refers to both fats and oils. Sometimes the word ‘lipid’ is used to describe fats.
