Term
What are the four large molecules?
Which three of them are macromolecules? |
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Definition
- Lipids
- Carbohydrates
- Proteins
- Nucleic Acids
All but lipids are macromolecules |
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Term
| What makes up a carbohydrate? Give four examples. |
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Definition
Monosaccharides chain together to create disaccharides and polysaccharides through glycosidic linkages.
Examples:
- starch
- glycogen
- cellulose
- chitin
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Term
| What is starch and what is it used by? |
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Definition
| Starch is polymers of glucose monomoers stored in chloroplasts of plants for energy. |
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Term
| What is glycogen and what is it used by? |
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Definition
| Glycogen is a glucose polymer stored by animals for energy. |
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Term
| What is cellulose and what is it used by? |
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Definition
| Cellulose is a beta glucose polymer. This means that the hydroxyl group on the 1-carbon is inverted, so everyother glucose molecule is flipped in order for dehyrdation reactions to occur and monomers to become polymers. It is used in plants, among other things, to create cell walls. |
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Term
| What is chitin and what is it used by? |
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Definition
Chitin is a beta glucose polymer like cellulose, except that its glucose monomer has a nitrogen-containing appendage. It is used in insects, among other things, to build exoskeletons. |
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Term
| What is a lipid? Give three examples. |
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Definition
A lipid is a hydrogen-carbon containing compound that is ussually insoluble in water.
Examples:
- fats
- phospholipids
- steroids
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Term
| What is fat made of? What is it used for? |
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Definition
Fat is made of glycerol binded through dehydration reactions to 3 fatty acids. Fatty acids are long hydrocarbon chains with a carboxyl group. This creates triacylglycerol.
Fat is used as cushion, to store energy and to fuel growth. |
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Term
| What is a phospholipid made of? What purpose does it serve? |
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Definition
A phospholipid is a triacylglycerol covalently bonded to two fatty acids and a phosphate group. Because the phosphate group has a negative charge, it often attracts a positive molecule to form the head.
Phospholipids are used to create membranes, consisting of two rows of phospholipids, in cells. The hydrophobic tails are facing inward while the hydrophilic (polar) heads face the cytoplasm and outside of the cell. |
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Term
| What is a steroid made of? What purpose does it serve? |
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Definition
A steroid is characterized by its four carbon rings fused to a varying chemical group.
An example of a steroid is a sex hormone. |
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Term
| What is a protein and what function does it serve? |
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Definition
| A protein is a polymer of amino acids which may consist of one or more polypeptides. They are a part of almost everything that happens in a cell. |
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Term
| What is an amino acid made of? What purpose does it serve? |
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Definition
An amino acid is a molecule containing a central carbon attached to a hydrogen, an amino group, a carboxyl group, and a varying side chain. Polymers of amino acids create proteins.
There are 20 in total and are linked through peptide bonds. |
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Term
| What are the four levels of protein structure? What type of bonds are involved with each? |
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Definition
1. Primary structure - The sequence of the amino acid backbones bound together through covalent peptide bonds.
2. The alpha helix and beta pleated sheet structures - Hydrogen bonds between every fourth amino acid create an alpha helix or beta pleated sheet structure.
3. The overall polypeptide shape - Side chain interactions (hydrogen bonds, covalent bonds, ionic bonds) give the polypeptide its shape.
4. (only some proteins) Polypeptides coming together - Polypeptides join through hydrogen, covalent, and ionic bonds. Either a globular or fibrous shape is created. |
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Term
| What does it mean to denature and renature a protein? |
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Definition
| A protein is denatured when exposed to severe conditions such as high temperature. This causes the protein to become unfolded. Proteins can be renatured its enviornment is restored to normal or with the help of chaperonin protein. |
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Term
| What are nucleic acids made of? What functions do they serve? |
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Definition
Nucleic acids are polymers of nucleotides. Nucleic acids are used in DNA.
Nucleotides are attached via the 5' or 3' carbon on the sugar molecule. When reading a strand of DNA or RNA, the nitrogenous bases are read from 5' (the phosphate group) to 3' (the OH group). |
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Term
| What is a nucleotide made of? What functions do they serve? |
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Definition
Nucleotides have two main components:
- A nucleoside, consiting of a nitrogenous base and a ribose molecule in RNA and a deoxyribose molecule in DNA
- A phosphate group
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Term
| What are the nitrogenous bases in nucleotides? Which bases pair with which? |
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Definition
The five nitrogenous bases:
- Adenine (A)
- Cytosine (C)
- Guanine (G)
- Thymine (T, ONLY IN DNA)
- Uracil (U, ONLY IN RNA)
Adenine pairs with Thymine OR Uracil
Cytosine pairs with Guanine |
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