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Flashcards in Biological Molecules Deck (13):
1

How are monosaccharides joined together

Condensation reactions, water is released and a glycosidic bond is formed

2

How are polymers broken apart

By hydrolysis reactions, glycosidic bond is broken using a water molecule

3

What is the test for sugars

Benedict’s, add benedicts then heat up, if positive will change colour from blue to red
Non reducing: add dilute hydrocholoric acid, then neutralise with sodium hydrogencarbonate, then do the benedicts test

4

What is starch

Glucose is stored as starch, it’s a mix of amylose and amylopectin, it’s insoluble, and tested by adding iodine

5

What is the structure of amylose

A long unbranched chain of alpha glucose, coiled, compact, good for storage

6

What is the structure of amylopectin

Long branched chains of alpha glucose, branches allow enzymes to break it down easily so energy can be released

7

What is glycogen

It’s the main energy storage molecule, long branched chain so energy can be released quickly, compact so good for storage

8

What is cellulose

It is long unbranched chains of beta glucose, forming a long straight molecule.
Linked by hydrogen bonds to microfibrils (providing support)

9

What’s the difference between a triglyceride and a phospholipid

One fatty acid is replaced by a phosphate group (hydrophilic) fatty acid tails (hydrophobic)

10

How are triglycerides formed

By condensation reactions, forming an ester bond when a molecule of water is released

11

How to test for lipids

Emulsion test:
Add ethanol, shake, add to water, milky colour indicates lipid

12

What is the structure of a protein

Made of amino acids
They all have a carboxyl group
Amino group
Carbon containing R/variable group
The difference is the variable group

13

How are polypeptides formed

By condensation reactions, peptide bonds are formed