1A - Biological Molecules Flashcards
1
Q
What are polymers?
A
- large complex molecules
- long chains of monomers joined together
2
Q
What are monomers?
A
- small, basic molecular units
3
Q
Name 3 examples of monomers
A
- Monosaccharides
- Amino acids
- Nucleotides
4
Q
What are Carbohydrates made from and what elements do they contain?
A
- Monosaccharides
- Carbon (C), Hydrogen (H) and Oxygen (O)
5
Q
Name 3 main monosaccharides
A
- Glucose
- Fructose
- Galactose
6
Q
What is glucose?
A
- a hexose sugar (contains six carbon atoms)
7
Q
Alpha and beta glucose are isomers. What are isomers?
A
- molecules with the same molecular formula as each other but atoms are connected in different ways
8
Q
What is a condensation reaction?
A
- two molecules join together by a new chemical bond
- water molecule is released
9
Q
What type of bond forms in condensation reaction?
A
- Glycosidic
10
Q
What is a disaccharide?
A
- Two monosaccharides joined together
11
Q
A glucose molecule and a fructose molecule join together to make what?
A
- Sucrose
12
Q
A glucose molecule and a galactose molecule join to make what?
A
- Lactose
13
Q
Two glucose molecules join to make what?
A
- Maltose
14
Q
What is a hydrolysis reaction?
A
- where polymers are broken down into monomers
- water molecule is added and breaks the chemical bond
15
Q
What are polysaccharides?
A
- more than two monosaccharides joined together
16
Q
Starch is a mixture which two polysaccharides?
A
- Amylose
- Amylopectin
17
Q
What is the structure of amylose?
A
- long, unbranched chain of alpha glucose
- coiled structure
- compact (good for storage)
18
Q
What is the structure of amylopectin?
A
- long, branched chain of alpha glucose
- side branches allow enzymes to break down glycosidic bonds easily
19
Q
What at the properties of starch?
A
- insoluble in water (hydrophobic)
- doesn’t affect water potential
- they can swell up (good storage)
20
Q
What do animals store excess glucose as?
A
- Glycogen
21
Q
What is the structure of glycogen?
A
- similar to amylopectin but loads more side branches
- side branches release glucose quickly
- compact molecule
22
Q
Where would you find cellulose in a plant?
A
- Cell wall
23
Q
What is the structure of cellulose?
A
- long, unbranched chains of beta glucose
- linked together by hydrogen bonds called microfibrils
- microfibrils provide structural support
24
Q
What is the structure of a triglyceride?
A
- one molecule of glycerol with 3 fatty acids attached to it
25
How are triglycerides formed?
- Condensation reactions
(ester bonds form between three glycerol molecules)
- water is released each time
26
What do the terms hydrophobic and hydrophilic mean?
- HydroPHOBIC means it's insoluble in water
| - HydroPHILIC means it's soluble in water
27
What is the difference between saturated and unsaturated fats?
- Saturated fats do NOT have any double bonds between carbon atoms
- Unsaturated fats have double bonds between carbon atoms
28
What is the difference between the structures of triglycerides and phospholipids?
- One of the fatty acid molecules in a triglyceride is replaced by a phosphate group
29
What are the properties of triglycerides?
- hydrocarbon tails contains a lot of chemical energy
- insoluble (don't affect water potential)
- causes osmosis
30
What are the properties of phospholipids?
- make up bilayer of cell membranes
- heads are hydrophilic and tails are hydrophobic - form double layer
- water-soluble substances can't easily pass through it
31
What is a dipeptide?
- Two amino acids joined together
32
What is a polypeptide?
- More than two amino acids joined together
33
What are the different groups in the structure of amino acids?
- Carboxyl group (COOH)
- Amino group (H2N)
- Variable/carbon containing group (R)
34
In a condensation reaction, what type of bond is formed between two amino acids?
- peptide bonds
35
What is the primary structure of a protein?
- sequence of amino acids in the polypeptide chain
36
What is the secondary structure of a protein?
- hydrogen bonds from between the amino acids
| - coil into a helix or fold into a pleated sheet
37
What is the tertiary structure of a protein?
- coiled or folded further
- more hydrogen and ionic bonds form
- 3D structure
38
What is the quaternary structure of a protein?
- several different polypeptide chains held together by bonds
- final 3D structure
39
What are the 4 different functions of proteins?
- Enzymes
- Antibodies
- Transport
- Structural
40
What are enzymes?
- speed up chemical reactions acting as catalysts
- spherical in shape
- soluble
- have roles in metabolism
41
What are antibodies?
- immune response
| - two light polypeptide chains
42
What are transport proteins?
- contain hydrophobic and hydrophilic amino acids
| - transport molecules and ions across membranes
43
What are structural proteins?
- physically strong
| - long polypeptide chains lying parallel and form cross links
44
How do enzymes lower the activation energy?
- make reactions happen at lower temperatures
| - speeding up the rate of reaction
45
Why do scientists prefer the ‘induced fit’ model than the ‘lock and key’ model?
- new studies showed the enzyme-substrate complex slightly changed shape to completely fit
46
What are the properties of an enzyme?
- very specific (only one complementary substrate can fit into an active site)
- tertiary structure of the enzyme determines the active site’s shape
- tertiary is determined by primary structure
- primary structure is determined by a gene
47
What are the 5 factors that can affect enzyme activity?
- Temperature
- pH
- Enzyme concentration
- Substrate concentration
- Inhibitors (competitive and non-competitive)
48
How does an enzyme become ‘denatured’?
- active site changes shape
| - enzyme and substrate can no longer fit together
49
How does temperature affect enzyme activity?
- more kinetic energy, so molecules faster
- enzymes are more likely to collide
- heavy vibrations causes bonds in enzyme to break if it’s too high
50
What is the difference between competitive and non competitive inhibitors?
- competitive bind to the active site
| - non competitive bind to the enzyme away from active site, causing it to change shape
