Macromolecules #2: Lipids Flashcards
Fat is what at room temperature?
Solid
Oil is what at room temperature
Liquid
Lipids are soluble in what? What are they not soluble in?-Because of what?
Organic solvents; Water-because they are all hydrophobic.
Lipids are primarily consumed for what?
Energy (specifically dietary lipids are primarily used/stored for energy.
What is a big part of lipids used for?
Insulation
Lipids are diverse groups, which means what?
There is no basic sub-unit
What elements do lipids contain?
Carbon, hydrogen, and oxygen but the H:O is not in a 2:1 ratio.
Lipids don’t come in what? What do lipids not have?
A specific ratio; there is no specific structural formula for lipids.
What are the 4 major sub-groups of lipids?
-Glycerides (Fats): Include triglycerides
-Phospholipids: Main component of cell membranes.
- Steroids
- Waxes
What differentiates a phospholipid from a triglyceride?
-Phospholipid: Two fatty acid chains.
-Triglyceride: Three fatty acid chains
What does cholesterol have that phospholipids and triglycerides don’t?
-Four hydrocarbon rings
- One hydrocarbon tail
What is one function of lipids (triglycerides)?
Long term energy storage, which is 2x energy that comes from carbohydrates.
How many times (numerically) of energy can lipids provide vs carbs? Why is that?
-2x to 3x of energy that carbs can give.
-Because lipids are massive - because of that lipids take time to break down - because of that lipids don’t provide energy immediately like carbs.
What is another reason why lipids don’t provide energy immediately?
Lipids do not always make themselves accessible to enzymes.
What are lipids the main source of? It is used as and is for?
-Potential Energy
-Used as needed and is for more long-term energy.
During sleep, humans burn what? Why?
-Lipids
-Bc of no rush for time + no need for any other short-term energy requirements.
Lipids take a lot of what to be broken?
Energy
What does lipids taking a lot of energy to be broken result in?
Only breaking down lipids when the need is necessary.
What is a 2nd function of lipids (triglycerides)?
Cushions/protects organs (e.g. kidney, reproductive organs, etc…)
What does each organ have?
A layer of lipids (fats) to cushion/protect it.
What is a 3rd function of lipids (triglycerides)?
Insulation: Helps maintain constant internal temperature
Why are triglycerides important for insulation?
Because humans cannot regulate internal body temperature; without them, we would not be able to regulate it otherwise.
Why would we use lipids for insulation rather than carbs?
Because carbs are much easier for enzymes to find than lipids-therefore, they do not last as long.
What is a more immediate purpose for triglycerides?
Insulation
What else are triglycerides used for?
Longer bursts of energy that are not needed immediately (needs consistent amount of energy over time).
What is the difference between carbohydrates and lipids (in terms of energy needs)?
Carbohydrates: For functions in flux.
Lipids: For functions at the same rate over time.
What is a fourth function of Lipids?
Structural-Cell Membrane
What are two lipids that are used for structural purposes in the cell membrane?
-Phospholipids
-Cholesterol
Phospholipid Function
Is what the cell membrane is made up of.
Cholesterol Function
A huge part that needs to be part of the diet; cholesterol = important (w/o it you would die).
Cholesterol has an important role in what?
Fluidity of cell membranes which allows certain materials in and out.
Cholesterol is what?
Basis for certain hormones.
Hormone do what?
Play a major role in endocrine system = Endocrine system runs the body.
What is a fifth function of lipids?
Vitamins and Hormones (Regulation of Biological Processes)
What is the function of Vitamin D?
A coenzyme
What type of environment do vitamins A, D, E, and K only function in?
A lipid environment
If there are no lipids, vitamins A, D, E, and K do not what?
Function
Vitamin D is in foods that we eat; if there are no lipids, is Vitamin D useful?
No, it is useless.
In the winter, Vitamin D is the only way to do what?
Maintain bones and tissues
What is a 6th function of lipids?
Waxes
What do waxes do?
Are a waterproof/protective coating
Where are waxes found?
- Human body: Nail Cuticle (Protects the openings of arterioles and capillaries to ensure no germs get in.)
- Leaves
What are glycerides (or triglycerides)?
Fatty acid chains bonded to glycerol
What do glycerol structures have?
Three spots for fatty acid chains.
Fatty acid chain functions depend on what?
Which fatty acids are connected.
What are glycerides (triglycerides) or fats used for?
Long-term energy storage and insulation.
Glycerides are defined by what
Their fatty acid components, which include the number of fatty acids (1 to 3), the length, and the degree of saturation (referring to if double bonds between carbons are present or not)
Glycerides can be
1 to 3 carbon hydrogen bonds or 1000 carbon hydrogen bonds.
Fatty acids can have
0 double bonds which would be saturated or have double bonds which would be unsaturated.
What is glycerol?
A 3 carbon chain, where each carbon has one hydroxyl group.
How many bonds does a glycerol molecule have?
8 bonds
Where does energy come from in triglycerides? Why?
Fatty acids, not glycerol - because there are only 8 bonds; 8 bonds is small
What are fatty acids?
Long chain hydrocarbons with a carboxylic acid at one end.
Fatty acids are usually what?
Hydrophobic (can be amphipathic)
Carboxylic acid always at the end of what?
Fatty acid chains
Fatty acids always hate what?
Water
However, fatty acids are what?
Amphipathic (having hydrophobic and hydrophillic components)
What do Monoglycerides have?
1 fatty acid
What do Diglycerides have?
2 fatty acids
What do Triglycerides have?
3 fatty acids
Saturated Glycerides: Describe bond and hydrogens.
-No double bonds
-Maximum number of hydrogens present
Saturated Glycerides: Physical state at room temperature
Solid
Saturated Glycerides: What type of chains
Straight chains that easily pack together
Saturated Glycerides: Implicated in what?
Coronary heart disease (CHD)
Saturated Glycerides: Found in what?
Meats, Dairy
Unsaturated Glycerides: Describe bond and hydrogens.
Has double bonds, less hydrogen due to double bonds present
Unsaturated Glycerides: Physical state at room temperature
Fluid
Unsaturated Glycerides: What type of chains
Tend to have bent chains that limit molecules from packing tightly together.
Unsaturated Glycerides: Cause what?
Less stable to off flavor development
Unsaturated Glycerides: Found in what?
*Vegetables, legumes, fish
Polyunsaturated Glycerides: Describe bond
2-5 double bonds
Highly-Saturated Glycerides
More than 5 double bonds
What are Omega 3 Fatty Acids good for?
Reducing Coronary Heart Disease (CHD)
What foods are high in Omega 3 Fatty Acids?
Fish
Examples of Omega 3 Fatty Acid
Linolenic Acid
Unsaturated Fatty Acids: Describe bonds
One or more double bonds between carbons
Unsaturated Fatty Acids: There is no what? This means…
No rotation around double bond; it is Rigid
Unsaturated Fatty Acids: Two types of double bonds
-Trans double bonds
-Cis double bonds
Trans double bonds characteristics
–Straight
–can pack closely
–Usually solid at room temp
Cis Double Bonds characteristics
–Kinked
–CanNOT pack together tightly
–usually liquid at room temp.
Difference between Saturated and Unsaturated Bonds
Saturated: Only single bonds
Unsaturated: Double bonds between 1 or more carbons
What happens during the formation of an ester?
When a molecule of glycerol reacts with one or more fatty acids an ester linkage results.
What is an ester linkage a result of?
A reaction between an alcohol and a carboxylic acid
What do phospholipids consist of?
*Phosphate and two fatty acids bonded to glycerol
Phospholipids are what?
A modified fatty acid
Phospholipids have what?
Two fatty acids tails and a phosphate head
What do phospholipids make up?
The cell membrane
Phospholipids components are what?
Altogether Amphipathic:
–Phosphate head = hydrophilic
–Fatty acid tails = hydrophobic
Phospholipids form what in water?
Micelles, liposomes or bilayers in water
Cell membranes (selectively permeable) are composed of what?
Bilayers of phospholipids.
Steroids are based on what?
The cholesterol molecule (4 rings)
Steroids are what?
Hydrophobic
Steroids are used as what?
Hormones (e.g. estrogen, testosterone, progesterone)
Steroids also have what? That prevents what?
a membrane component; aggregation of phospholipids (maintains fluidity)
Why is cholesterol important in the body? (4 reasons)
*Hormone production
*Membranes
*Vitamin D
*Absorption of fats
What foods are high in cholesterol? (3 of them)
*Organ meats
*Eggs
*Shellfish
Waxes are extremely what?
Extremely hydrophobic
Example of a wax
Cutin: cuticle of leaf
