Carbohydrates & Lipids Flashcards
Define polymer
a long molecule consisting of many similar or identical monomers linked by covalent bonds
ie, a macromolecule
Define monomer
One of the repeating molecule units that builds macromolecules/polymers
Describe the process of synthesis
Dehydration removes water molecule to link the monomers in covalent bonds to form polymers
Describe the process of break down
Hydrolysis is the addition of water molecule to a polymer to break apart the covalent bonds and separate monomers
What process builds macromolecules/polymers?
Dehydration reactions connect monomers
What are the 3 common elements in carbohydrates?
carbon, hydrogen, oxygen
Define carbohydrate
An organic compound used to store sugar and composed of multiple monosaccharides
What is the general equation for simple sugars?
CH2O
What functional groups do carbohydrates include?
multiple hydroxyl groups and a carbonyl group (ketones and aldehydes)
Define monosaccharide and give an example
The simplest carbohydrates (simple sugars) from which more complex carbohydrates are built
They contain either 3, 5, or 6 Carbon atoms
ex. Glucose
What is name for the sugar if the carbonyl group is at the end of the carbon chain?
Give examples
Aldose
ex. glucose, ribose
What is name for the sugar if the carbonyl group is within the carbon chain?
Give examples
Ketose
ex. fructose
Define triose
Give 3 examples
A 3 Carbon sugar
ex. glucose, galactose, and fructose
Define pentose
A 5 carbon sugar
ex. ribose
Define hexose
A 6 carbon sugar
What are the 4 functions of carbohydrates?
Sources of energy
building blocks for other molecules
storage of energy
structural components
Define disaccharides
Sub units of carbohydrates composed of two monosaccharides joined by covalent bonds (aka glycosidic linkages) during a dehydration reaction
What is the name of the covalent bond that connects monosaccharides?
glycosidic linkage
Give two examples of disaccharides
ex. sucrose (glucose + fructose)
ex. lactose (glucose + galactose)
Define polysaccharides
macromolecules/polymers made up of hundreds to thousands of monosaccharides joined by glycosidic linkages
Some are used to store sugars
How do plants store glucose?
in long chains as STARCH in 2 mostly helical forms:
- amylose
- amylopectin
Define amylose. What kind of linkage does it have?
An unbranched form of starch that plants use to store glucose.
Alpha 1-4 linkage
Define amylopectin. What kind of linkage does it have?
A branched form of starch that plants use to store glucose
Alpha 1-4 and 1-6 linkages
How do animals store glucose?
As GLYCOGEN
Define glycogen. What kind of linkage does it have?
The extensively branched form of stored sugars/glucose in animals
1-4 and 1-6 linkages
How many days worth of sugars do humans have stored in muscle and liver cells?
About one days worth
What is an example of a structural polysaccharide?
Cellulose in plant cells
Chitin in arthropods
What kind of glucose linkage does cellulose have?
Beta with 1-4 linkages
What structure will a beta glucose molecule have?
OH attached to carbon 1 above the plane of the molecule
What structure will an alpha glucose molecule have?
OH attached to carbon 1 below the plane of the molecule
Describe chitin (what kind of linkages)
A glucose containing compound that arthropods use to make their exoskeletons, also found in fungal cell walls
Has beta glucose with 1-4 linkages and also contains nitrogen
Define lipids
A diverse group of hydrophobic molecules that are not polymers but linked during dehydration reactions.
Lipids include:
fats and phospholipids
What are 3 kinds of lipids?
- fats
- phospholipids
- steroids
What are the 3 main functions of fats?
Fats are a lipid
Function in energy storage, protecting organs, and insulating body
What are the two common elements that make up fats?
C-H (aka hydrocarbons)
What are the 4 components of a fat?
3 fatty acid molecules are joined to a glycerol molecule by ester linkages
Which 3 functional groups can be part of a fatty acid?
Carboxyl
Hydroxyl
Ester
Fatty acids can be the same 3 or different
What are the 2 kinds of fats?
- Saturated
2. Unsaturated
What are the 2 kinds of fatty acids?
Essential
Non-essential
Define saturated fats
A type of lipid (fat) that contains fatty acids with the maximum number of hydrogens bonded to the carbon chain possible
(ie, no double bonds)
Are saturated fats liquid or solid at room temperature? Why?
Solid because they lack double bonds so they are more flexible and easier to pack down
What is a natural source of saturated fats?
Animal fats
Define unsaturated fats
A type of lipid (fat) that contains fatty acids with double bonds in the carbon chain, removing some of the hydrogens
Are unsaturated fats liquid or solid at room temperature? why?
Liquid because they contain cis-double bonds and cannot pack together as closely
What is a natural source of unsaturated fats?
Most plant and fish oils
Define essential fatty acids. Give an example
Unsaturated fats that must be supplied by the diet because the human body cannot produce them
ex. Omega-3
Define non-essential fatty acids
Saturated fats that are made by the human body
Define phospholipids
A type of lipid that is composed of two fatty acids and a phosphate group attached to glycerol
Are phospholipids hydrophobic, hydrophilic, or amphipathic?
Amphipathic
The fatty acids are hydrophobic and the phosphate groups (and attachments) are hydrophilic
Define micelle
The spherical structure formed by phospholipids with the phosphate head facing out and the fatty acid head facing inwards
Define phospholipid bilayer
The layer that forms cell membranes that has the hydrophilic unsaturated fats/phosphate group on the outside and the hydrophobic saturated fats on the inside
What is the name of the bond between lipid subunits?
Ester linkage
Define ester linkage
A covalent bond formed by a dehydration reaction between a hydroxyl group and a carboxyl group to leave behind an ester
Define steroids
Lipids characterized by a carbon chain consisting of four fused rings
How are steroids differentiated?
By the different chemical groups attached to the rings
What are the 3 main functions of steroids?
- Cholesterol is a major steroid that is required for building and maintaining membranes
- Hormones can be made from cholesterol and help coordinate activities of the body
- Precursors to vertebrate sex hormones
T or F: Lipids are polymers and considered macromolecules
False
Define glycerol
An alcohol with each of the 3 carbons connected to a hydroxyl (OH) group
Define fatty acid
A long carbon chain (16-18) with one end being a carboxyl group and the rest is hydrocarbons
What is the result of an ester linkage?
A fat consisting of three fatty acids attached to one glycerol aka a triglyceride
Why are phospholipids essential for cells?
They are major constituents of cell membranes
Describe sucrose
A disaccharide formed by the glycosidic linkage of 1 glucose monomer and 1 fructose monomer
Describe fructose
A hexose ketose monosaccharide
Describe glucose
The most common monosaccharide. It contains a carbonyl group and multiple hydroxyl groups
Describe lactose
the disaccharide sugar present in milk formed by the glycosidic linkage of one glucose monomer and one galactose monomer
Describe starch
A polysaccharide composed of multiple glucose monomers. These glucose monomers can be formed in either amylose or amylopectin forms.
Describe glycogen
A polysaccharide that animals store, made of a polymer of glucose like amylopectin but more extensively branched
Where is glycogen usually stored in animals?
Liver and muscle cells
What process releases glucose from starch or glycogen?
Hydrolysis of the glucose
