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Flashcards in Chemistry for life Deck (77)
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1
Q

What is a covalent bonding

A

Formed when an atoms share electrons

2
Q

What is an ionic bonding

A

Attractive forces between oppositely charged ions

3
Q

What does

PANCAKE stand for

A

Positive anode Negative cathode

4
Q

What are important anions in biology

A

.Nitrate ions (NO3-)
.Phosphate ions (PO43-)
.Chloride ions (CL-)
.Hydrogen carbonate ions (HCO3-)

5
Q

What are important Cations in biology

A

.Sodium ions (Na+)
.Calcium ions (Ca2+)
.Hydrogen ions (H+)
.Magnesium ions (mg2+)

6
Q

What bonds do water contain

A

Hydrogen bonds

7
Q

What are the important properties of water

A

1)Water is a polar solvent
2)Water is an excellent transport medium
3)Ice is less dense than water
4)Water is slow to absorb and release heat
.Water is liquid so it cannot be compressed
.Water molecules are cohesive
.Water molecules are adhesive
.Water has a high surface tension

8
Q

What is meant by water is cohesive

A

The forces between the molecules stick together

9
Q

What is meant by water is adhesive

A

They are attracted to different molecules

10
Q

Why does water have a high surface tension

A

The attraction between the water molecules is greater than the attraction between water molecules and the air

11
Q

What is the difference between glycogen and starch

A

Glycogen is used as animal storage and starch is used as plant storage
Glycogen has shorter 1,4 glycosidic bonds
Glycogen is more compact
Glycogen is more branched

12
Q

What are the functions of cellulose?

A

.Insoluable
.Gives cell Turgidity
.Allows for some movement

13
Q

What molecule is formed in the hydrolysis of cellulose

A

B-glucose

14
Q

What is the difference between Glycogen and cellulose

A

Glycogen contains a-glucose units whereas cellulose contains both a and b-glucose unit
Cellulose is in plants whereas glycogen is in animals

15
Q

Describe triglycerides

A

Hydrophobic

insoluble

16
Q

Describe phospholipids

A

Hydrophilic heads and hydrophobic tails

17
Q

What’s the main difference between triglyceride and phospholipid

A

A phospholipid has one glycerol, two fatty acids, and a hydrophilic phosphate group
Triglyceride has three fatty acids
Triglyceride has hydrophobic head whereas phospholipid has hydrophilic heads

18
Q

What are the functions of:

a) Triglycerides
b) Phospholipid
c) Cholesterol

A

a) Energy store and fat
b) cell membrane and cell signaling
c) Cell membrane fluidity and Steroid hormone

19
Q

What is the primary structure

A

The specific sequence of amino acids in a protein

20
Q

What is the secondary structure

A

The coiling and pleating of parts of the amino acids

21
Q

What is the tertiary structure

A

The overall 3D structure of the protein

22
Q

what are the Three types of bonding that occur within the R-group in tertiary structure

A

Disulphate bond
Hydrogen bond
Ionic bond

23
Q

When do the following bonds occur:

a) Disulphate bond
b) Hydrogen bond
c) Ionic bond

A

a) Between amine group with sulfate ions (between cysteine groups)
b) between delta +ve and delta -ve R-groups
c) Between completely ionic R-groups

24
Q

What are the two main types of tertiary structured proteins

A

Globular and fibrous

25
Q

What is the structure and function of globular proteins

A
.Rolled into balls 
.Usually soluable 
.metabolic roles 
Examples of globular proteins 
.Enzyme 
.Antibodies 
.Haemoglobin
26
Q

What is the structure and function of fibrous proteins

A
.Form fibrous
.Usually insoluble 
.Structural roles
.Examples of fibrous proteins 
.collagen
.Keratin
27
Q

What is a quaternary structure

Give an example

A

a protein made of more than one polypeptide

Haemoglobin and collagen

28
Q

What is the structure and function of haemoglobin

A
.Globular
.Soluable
.Many amino acids 
.Contains prostheic group (Haem)
.Alpha helix
29
Q

What is the structure and function of collagen

A
.Fibrous 
.insoluable 
.35% glycine
.No prosthetic group
.Has a left handed helix structure
30
Q

What are the properties of collagen

A

.High tensile strength
.insoluable
.not elastic
.flexable

31
Q

What are

a) glycoproteins
b) lipoproteins

A

a) protein with a carbohydrate prosthetic group

b) protein with lipid prosthetic group

32
Q

What are the properties of glycoproteins

A

.Water holding
.Thyre slippery and viscous
.Helps mucus produced in the stomach protect the protein wall from digestion

33
Q

What are the properties of Lipoproteins

A

.Important in the transport of cholesterol in the blood
They have a high density (HDL) and low-density lipoproteins (LDL)
HDLS contain more proteins than LDLS hence why they are denser

34
Q

What is a nucleotide made up of

A

Phosphate group
sugar
nitrogenous base

35
Q

What is ATP

A

A nucleotide that has:
three phosphate groups
ribose sugar
adenine base

36
Q

What is the removal of the third phosphate group catalysed by

A

ATPase

37
Q

What happens when energy is needed from ATP

A

A third phosphate group is taken off

38
Q

When the third phosphate is removed what does the ATP molecule break up into

A

ADP +Pi

39
Q

What are nucleic acids

A

Polymers made up of many nucleotides monomer units that carry all the information needed to form new cells

40
Q

What are the two main types of nucleic acids in our body

A

DNA and RNA

41
Q

What is the difference between pyrimidines and purines

A

Pyrimidines have a single one ring nitrogenous base whereas purines have a double nitrogenous base ring

42
Q

What are the three different types of pyrimidines

A

Thymine
Cytosine
Uracil

43
Q

What are the two different types of purines

A

Adenine

Guanine

44
Q

How do you know whether the sugar is ribose or deoxyribose on the nucleic acid

A

If the atom attached to the second carbon on the molecule is H its deoxyribose
If the atom attached to the second carbon on the molecule is OH its ribose

45
Q

How is a long chain of nucleotides formed

A

The phosphate group that attaches to the carbon number 5 on the sugar below forms attachment with carbon number 3 on sugar above
This pattern keeps going

46
Q

What are the complementary base pairings

A

A-T

G-C

47
Q

which of the complementary base pairing has a:
A)double bond
b)triple bond

A

a) Adenine and thymine

2) Guanine and cytosine

48
Q

what is a genome

A

The entire genetic material of an organism

49
Q

What is DNA helicase

A

The enzyme involved in unzipping the two strands of the DNA molecule

50
Q

What is DNA polymerase

A

The enzyme involved in DNA replication that lines up and catalyses the linking up of the nucleotides along the template strand

51
Q

What are the steps for DNA replication

A

1) You start with a double helix
2) The nucleotides match up to its complementary base
3) When the DNA replicates, DNA helicase unzips the two strands of the DNA molecule and breaks the hydrogen bonds
4) Exposed bases match to another free nucleotide and are zipped back together by the DNA polymerase
5) DNA ligase catalyses the formation of phosphodiester bonds between two strands of DNA
6) This forms two new strands of DNA identical with the original piece

52
Q

Which out of transcription and translation comes first

A

Transcription

53
Q

Where does transcription take place

A

in the nucleus

54
Q

Explain the process of transcription

A

1) RNA polymerase connects complementary RNA bases to the DNA
2) These RNA bases are bonded together to form mRNA
3) mRNA goes out of the nucleus into the cytoplasm where it attaches to a ribosome
4) The ribosome is made of rRNA
5) Ribosome builds our protein the next step called translation

55
Q

Explain the process of Translation

A

1) tRNA look for complementary bases (codons) on the mRNA and when they find it, they transfer their amino acid
2) When tRNA eventually leaves, it leaves behind its amino acid
3) These amino acids are held together by a peptide bond
4) At the end of the mRNA, there’s a stop codon

56
Q

What are polysomes

A

Groups of ribosomes, joined by a thread of mRNA, that can produce large quantities of a particular protein

57
Q

What are the types of gene mutations

A

1) Substitution
2) Insertion
3) deletion

58
Q

What do the following types of gene mutations mean:

a) Substitution
b) Insertion
c) deletion

A

a) You have the wrong base matched
b) Have extra bases added in
c) A base is removed

59
Q

What is a chromosomal mutation

A

Changes in the position of entire genes within a whole chromosome

60
Q

What is a whole-chromosome mutation

A

The loss or duplication of a whole chromosome

61
Q

How is sickle cell disease caused

A

By a change of one base in one codon

62
Q

What is a mutagen

Give an example of one

A

Anything that increases the rate of mutation

An example is x-rays

63
Q

What are Enzymes

A

Proteins that have very specific shapes and are a biological catalyst

64
Q

What is meant by an induced fit

A

The active site changes its shape to bind the substrate

65
Q

How do enzymes catalyse reactions

A

They reduce the activation energy

66
Q

What are the lock and key theory

A

The model that explains enzyme action by an active site in the protein structure that has a very specific shape

67
Q

What is formed in the lock and key theory

A

1) Enzyme-substrate complex

2) Products

68
Q

What does the enzyme-substrate complex look like

A

The substrate has to be a complementary shape to fit the active site

69
Q

What is the induced fit theory

A

A modified version of the lock and key hypothesis for enzyme action where the active site is considered more flexible

70
Q

What are enzyme inhibitors

A

Substances that slow down enzymes or stop them from working

71
Q

What are the two main types of reverse inhibition

A

1) competitive inhibitors

2) non competiitve inhibitor

72
Q

What do the following enzyme reverse inhibitors mean:

a) competitive inhibitors
b) non-competitive inhibitor

A

a) It’s similar to the shape of the substrate molecule and competes with it for the active site of the enzyme
b) The inhibitor does not compete for the active site but forms a complex with the enzyme or enzyme/substrate complex and changes the shape of the active site so it can no longer catalyse the reaction

73
Q

What is meant by a reverse inhibition

A

Inhibition of action if an enzyme by an inhibitor that does not permanently affect the functioning of the enzyme

74
Q

What is meant by an irreversible inhibition

A

Inhibition of the action of an enzyme that is permanent and can not be undone

75
Q

What can affect enzyme activity

A

PH

temperature

76
Q

What are regulatory enzymes

A

Enzymes that have a site that’s separate to the active site where another molecule can bind to have either an activating or inhibitory effect

77
Q

What are End-product inhibition

A

A control system in many metabolic pathways in which an enzyme at the beginning of the pathway is inhibited by one of the end products of the reaction