2.1.2 Biological Molecules Flashcards
1
Q
what elements make up carbohydrates?
A
- carbon
- hydrogen
- oxygen
2
Q
what elements make up lipids?
A
- carbon
- hydrogen
- oxygen
3
Q
what elements make up proteins?
A
- carbon
- hydrogen
- oxygen
- nitrogen
- sulfur
4
Q
what elements make up nucleic acids?
A
- carbon
- hydrogen
- oxygen
- nitrogen
- phosphorous
5
Q
what are the three types of saccharides?
A
- monosaccharides
- disaccharides
- polysaccharides
6
Q
what is glucose an example of?
A
a hexose monosaccharide
7
Q
how many isomers does glucose have?
A
2 ——> • alpha
• beta
8
Q
what is a condensation reaction?
A
joins monomers like monosaccharides by chemical bonds and it involves the elimination of water molecules
9
Q
what is hydrolysis?
A
water is added to break a chemical bond between two molecules
10
Q
what are three examples of disaccharides?
A
- maltose
- lactose
- sucrose
11
Q
what is maltose made up of?
A
2 alpha glucoses
12
Q
how are triglycerides made?
A
when 3 fatty acids are joined to glycerol by an ester link
13
Q
type of reaction when glycerol forms an ester bond with fatty acids?
A
condensation reaction
14
Q
what are the functions of triglyceride?
A
- energy source
—> can be broken down in respiration to release energy - energy store
—> insoluble and stored in tissues - insulation
—> bubbler in whales - buoyancy
—> helps with floating aquatic animals - protects vital organs
- insoluble
—> doesn’t affect water potential
15
Q
what is the structure of a phospholipid molecule?
A
- hydrophilic head
—> contains phosphate and glycerol - hydrophobic tails
—> has saturated and unsaturated fatty acids
16
Q
what do phospholipids make up?
A
cell surface membranes
17
Q
what are the functions of cholesterol?
A
- makes sterioid hormones (testosterone and oestrogen)
- makes vitamin D
- regulates cell membrane fluidity
18
Q
what is the general structure of an amino acid?
A
- amine group on the left
- r group on top/bottom middle
- carboxyl group on the right
19
Q
what group is unique to each amino acid?
A
the R group
20
Q
what bond forms when two amino acids join together?
A
peptide bonds
21
Q
how are two amino acids joined together?
A
OH and H form H2O in a condensation reaction
22
Q
what is the primary structure of protein?
A
the sequence of amino acids bonded by peptide bonds
23
Q
what is the secondary structure of protein?
A
- folding of the polypeptide chain which are held in place with hydrogen bonds
- hydrogen bonds formed between slightly positive hydrogen and slightly negative oxygen in the R group
- forms either alpha helix or beta pleated sheets
24
Q
what is the tertiary structure of the protein?
A
- further folding of protein
- disulphide bridges
- ionic bonds
- hydrophobic R groups orientate towards centre of protein
- hydrophilic R groups orientate towards outside of protein
25
what’s the quaternary structure of proteins?
more than 1 polypeptide chain
26
how does the structure of phospholipid molecules allow for the formation of plasma membranes?
- phosphate is **hydrophilic**
- fatty acid tails are **hydrophobic**
- **heads orientate** towards **water**
27
why is water having a high boiling point important for organisms?
- a **lot of energy** is needed to **break** the many **hydrogen bonds**
- e.g stable water temp for **aquatic animals** and less energy spent on **temp control**
28
why is ice being less dense than water important?
- creates **insulating barrier**
- water below **doesnt freeze**
- organisms like fish can move **underwater**
- provides **habitats** for animals like polar bears onto of ice & fish underwater
29
what is cohesion and why is it important?
- hydrogen bonding in water
- creates **high surface tension** for insects to walk on water
30
what is adhesion and why is it important?
- water’s attraction to **other surfaces**
- e.g water flowing through **xylem**
31
why is water acting as a solvent important?
- allows **ionic compounds** to **separate**
- allows **transport**
- **medium** for reactions
32
why is water being able to evaporate important?
- cooling mechanism
- takes heat away from body e.g sweating
33
what is specific heat capacity?
the amount of energy needed to **heat** up a **substance by 1°**
34
what is latent heat?
amount of energy for a substance to **change state**
35
why is high specific heat capacity and high latent heat important for water?
- creates a **stable temperature**
- enzymes can work at their **optimum temperature**
- gases remain soluble
36
what is capillary action in water and why is it important?
- ability of water to **move up narrow vessels**
- e.g water moving up in xylem in plants
37
why is water a good solvent?
- molecules are **polar**
- enables water molecules to **bind to solute molecules**
38
how do hydrogen ions help plants?
regulates pH
39
how do sodium ions help plants?
regulates **water potential**
40
what are the two types of proteins?
- fibrous
- globular
41
what are the properties of fibrous proteins?
- **insoluble** in water as a lot of **hydrophobic R groups**
- very **strong** as many **disulphide bridges**
42
what are the three main fibrous proteins?
- keratin (hair)
—> **disulphide bridges** for strength
- elastin (alveoli)
—> **recoils** after being deformed
- collagen (skin)
—> flexible but **doesn’t stretch**
43
what are the properties of globular proteins?
- compact, **3D shape**
- **soluble** in water
- have a **prosthetic group**
44
what are the three globular proteins?
- insulin (**specific fixed** shape)
- haemoglobin (can **change** shape)
- catalase (**specific fixed** shape)
45
how can R groups interact to determine tertiary structure of protein?
- **hydrophobic R groups** on **inside**
-**hydrophilic** R groups on the **outside**
- disulphide bridges
- ionic bonds **between oppositely charged** particles
46
how do the properties of water result in surface tension?
- water molecules are **polar**
- they form **hydrogen bonds**
- therefore they are **cohesive**
47
what are the properties of cholesterol?
- insoluble
- small size and **flattened** shape
—> allows it to fit between **phospholipid molecules**
48
what must you make sure you do in chromatography and why?
1. hold plate by **the side**
—> to **prevent contamination**
2. put solvent **above** pencil line
—> to prevent spots **dissolving**
3. place **lid on beaker**
—> to **prevent evaporation**
4. repeat and **find mean**
—> improves **accuracy**
49
how can a change in DNA base sequence for a protein change the structure of the protein?
- change in **primary structure**
- change in **hydrogen bonds**
- alters **tertiary structure**
50
how do the properties of water result in sweating being an affective way to cool animals down?
- **large latent heat** of vaporisation
- takes a lot of **thermal energy**
- to **break hydrogen bonds**
51
what’s a conjugated protein?
contains **non-protein** groups like a **prosthetic group**
52
what’s the chemical formula of glucose?
C6H12O6
53
how can lipids increase bouyouncy?
**proteins** are **more dense** than **lipids**
54
how can the structure of galactose allow it to be used as a respiratory substrate?
- bonds contain **energy**
- **soluble** so it can **move**
- **OH forms H bonds** with **water**
55
how can a calorimeter be used to measure the concentration of a sugar?
- **zero the calorimeter**
- use a **red filter**
- use series of **known conc.** of sugar
- use results to construct a **calibration curve**
56
why would glycine appear at the top of the chromatography layer?
- **rate of movement** is **determined** by **solubility**
- **glycine is more soluble** than other amino acids
57
how does the structure of triglycerides make it suitable for energy storage?
- contain **many C-H bonds**
- **energy is released** when **bonds are broken**
- they are **hydrophobic**
- **do not cause water uptake** by **osmosis**
58
true or false: amylopectin contains 1,4 and 1,6 glycosidic bonds
true
59
write in order of solubility: ribose, amylose, glucose, amylopectin
- glucose **MOST** SOLUBLE
- ribose
- amylose
- amylopectin **LEAST** SOLUBLE
60
What’s the carbohydrate molecule used to store energy in animals?
Glycogen
61
What’s the carbohydrate molecule used to store energy in plants?
Starch
62
what are the advantages of storing glycogen?
- **insoluble** so **no effect on water potential**
- **compact**
- **rapid release** of **glucose**
63
compared to amylopectin, what properties does glycogen have?
- more **branched**
- more **compact**
- more **free ends** for **glucose** to be **added**
- **speeds** up **glucose release**
64
how can glycogen be used as a respiratory substance?
- **soluble** so can **move**
- **OH forms H bonds** with **water**
- **bonds** contain **energy**
65
how does freezing change properties of blood plasma?
- frozen plasma **can’t act as a solvent**
- **can’t flow**
- has an **open tetrahedral structure**
- frozen plasma **less dense** than normal blood
66
what do bacteria need to grow?
- carbon, hydrogen and **other elements**
- **absence of other elements** is a **limiting factor**
67
what’s the molecular formula of lactose?
C12H22O11
