Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology > Biomolecules > Flashcards

Biomolecules Flashcards

carbs, lipids, proteins, water, ions, enzymes, DNA, viruses

1
Q

What are monosaccharides, disaccharides and polysaccharides? Give examples of each

A

Monosaccharides: single sugar monomers
e.g glucose, fructose, galactose
Disaccharides: 2 molecules of sugar
e.g maltose, sucrose, lactose
Polysaccharides: multiple molecules of glucose
e.g starch, glycogen, cellulose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the 2 isomers of glucose and how do they differ?

A

Alpha and Beta glucose.
The hydroxyl groups on carbon 1 are opposite for both.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is ribose? Give it’s chemical formula too

A

It’s a pentose sugar containing 5 carbons.
Chemical formula is C5H10O5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a condensation reaction? Draw one for formation of maltose

A

A reaction that joins monosaccharides to form disaccharides and polysaccharides.
Produces a water molecule.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the reverse reaction of a condensation reaction called?

A

Hydrolysis. The water molecule is used to split the disaccharides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is starch made of?
What are their monomers?

A

Amylose and amylopectin.
Both are made of alpha glucose.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe structure of amylose

A

Has 1,4 glycosidic bonds which cause it to coil. Hydrogen bonds between the coil hold and stabilise it.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe structure of amylopectin

A

Has 1,4 and 1,6 glycosidic bonds. 1,6 glycosidic bonds cause branching

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does structure of starch aid it’s function?

A

Starch is a storage molecule for glucose.
Coiling makes it compact so large amount of glucose can be stored in a small space.
Branching allows starch to be hydrolysed quicker to release glucose.
Starch is insoluble so it doesn’t affect the water potential of plant cell’s cytoplasm.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe structure of glycogen

A

Made of highly branched molecules of amylopectin
Has 1,4 and 1,6 glycosidic bonds
Has more branching than amylopectin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does glycogen’s structure aid it’s function?

A

Increased branching because animals are more active so they need a quicker source of glucose.
Is insoluble so doesn’t affect water potential of storage cell’s cytoplasm.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe structure of cellulose

A

Made of beta glucose monomers with 1,4 glycosidic bonds
Every other beta glucose molecule is inverted so it forms straight chains called microfibrils.
There are hydrogen bonds between chains.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does cellulose’s structure aid it’s function?

A

Forms straight chains which gives it a regular arrangement
Joined with hydrogen bonds between chains which holds the chains tightly.
Gives cellulose large strength to support cell wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What’s the difference between a monoglyceride, diglyceride and triglyceride?

A

Monoglyceride: contains 1 fatty acid
Diglyceride: contains 2 fatty acids
Triglyceride: contains 3 fatty acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What’s the difference between saturated and unsaturated fatty acids?

A

Saturated fatty acids have no double bonds between carbon atoms
Unsaturated do have double bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Double bonds cause kinking. How does this affect the properties of unsaturated fatty acids?

A

They have a random arrangement due to the kinking which increases fluidity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

List the functions of triglycerides

A

They are stored in fat cells which form adipose tissue.
Adipose tissue is used as an energy store but also helps to insulate and protect the body.
Saturated fatty acids have a regular alignment which makes them compact.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe structure of phospholipids

A

Consist of 2 fatty acids attached to a glycerol molecule and a phosphate group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

In which property do fatty acids and the phosphate group differ in?

A

Fatty acids are hydrophobic so they are not attracted to water.
Phosphate group is hydrophilic so it associates with water.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What do phospholipids form in aqueous environments?

A

Phospholipid bilayer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe steps for lipid test

A
  1. Add food sample into test tube and add ethanol
  2. Shake
  3. Place food and ethanol mixture in test tube with water
  4. Shake
  5. If lipids present it’ll turn from colorless to milky emulsion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Name the 3 uses of lipids

A
  1. Energy storage - lipids store more energy than carbs but they aren’t hydrolysed as easily as carbs
  2. Waterproofing - lipids are hydrophobic so can be used for waves etc
  3. Insulation - lipids are poor conductors of heat
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Name and describe first 3 properties of water

A
  1. High heat capacity - A large amount of heat energy is needed to raise the temperature of water significantly.
  2. Large latent heat of vaporisation - large amount of energy is lost through water cooling down due to evaporation.
  3. strong cohesion - cohesion is bond between water molecules. Due to polarity, water molecules are attracted to each other, forming hydrogen bonds. These allow water to flow as a continuous stream.
24
Q

Name and describe last 2 properties of water

A
  1. Important solvent - opposite charges of water attract other molecules causing them to separate (dissolve)
  2. Metabolite - water is involved in condensation and hydrolysis reactions directly
25
What is a cation and anion?
Cation is a positive ion Anion is a negative ion
26
What is the monomer of protein? Draw it's structure and label the different groups
Amino acid is the monomer. It has an amino group, carboxyl group and R group.
27
What bond is formed when 2 amino acids join together? Name the new product
They join to form a dipeptide with a peptide bond in between.
28
Describe the primary, secondary, tertiary and quaternary structures of proteins
Primary - order of amino acids if determined by order of bases in a gene. Secondary - amino acids form either alpha helix or beta sheet. Both are held by hydrogen bonds. Tertiary - folding of polypeptide chain into 3d shape. Held together by ionic, hydrogen or disulfide bonds between R groups. Quaternary - only in proteins with more than 1 polypeptide chain
29
What are globular proteins?
Are small, ball shaped and compact Are soluble e.g enzymes, haemoglobin
30
What is the induced fit hypothesis?
Even if the substrate is not perfectly complimentary to the shape of the active sit, the active site can change shape to mould itself around the substrate better. Hydrogen bonds will form from active site to hold the substrate in place
31
What forms when substrate binds to active site?
Enzyme - substrate complex
32
What is activation energy?
energy needed to start a reaction
33
Name the 4 factors which affect enzyme activity
1. enzyme conc 2. substrate conc 3. temperature 4. pH
34
How does pH affect enzyme activity?
Enzymes work best at pH 7 (optimum) Above and below the optimum, the H+ and OH- ions will affect the ionic and hydrogen bonds holding enzymes' tertiary structure in place. So active site changes shape and enzyme is denatured.
35
Describe competitive inhibition?
inhibitor and substrate are similar shapes so BOTH are complimentary + competing to bind to active site. If competitive inhibtor reaches active site first, it blocks substrate from binding instead. SO NO ENZYME SUBSTRATE COMPLEXES FORMED
36
Describe non competitive inhibition
non - competitive inhibitor binds to ALLOSTERIC site (any place on enzyme other than active site). causes active site to change shape so no longer complimentary to substrate. substrate can't fit SO NO ENZYME SUBSTRATE COMPLEXES FORMED
37
Describe end - product inhibition
It's a form of negative feedback. When too much end product, non competitive inhibitors stop enzymes. So products stop being formed as no enzyme substrate complexes.
38
What is a DNA nucleotide made out of?
phosphate group deoxyribose sugar nitrogenous base
39
Which direction do the nucleotides run in?
They run in opposite directions BUT both run from 5 prime to 3 prime
40
How is a phosphodiester bond formed?
Condensation reaction between a phosphate group of 1 nucleotide and pentose sugar of another forms phosphodiester bond.
41
What is DNA's function and how is it well adapted for it?
It's responsible for passing info from cell to cell via replication. Very stable due to hydrogen and covalent bonds. H bonds between 2 strands mean it can be easily unzipped in replication and protein synthesis. large molecule COILED for compact storage
42
What is a gene
Section of DNA that codes for a particular protein
43
What is a triplet codon
sequence of 3 bases that code for an amino acid
44
How is RNA different to DNA
T is used in DNA but U is used instead in RNA sugar in backbone of RNA is ribose RNA is single stranded
45
Outline the steps of DNA replication
1. DNA helicase unzips the 2 DNA strands by breaking H bonds 2. Free nucleotides are brought to template strand by DNA polymerase 3. This forms phosphodiester bonds between adjacent nucleotides. 4. strand is built in 5 prime to 3 prime direction 5. For lagging strand, DNA polymerase joins adjacent nucleotides in okazaki fragments 6. Ligase enzyme joins up both strands to form new DNA strand.
46
Explain semi-conservative replication (N14 & N15)
2 samples of E coli grown: 1 on N14 one on N15 N15 is heavy, when it was grown on N14 the 1st round, the DNA produced was intermediate (showing 1 strand if DNA was N14 light, 2nd was N15 heavy). When it was grown on N14 again, the results showed 1 line at intermediate and the other at light. This showed of the light DNA both strands were N14 light BUT for intermediate DNA, one strand was N15 and one N14 showing semi-conservative replication.
47
What is protein synthesis
Transcription and Translation
48
Outline steps of Transcription
1. Section of DNA unzips as H bonds between 2 strands are broken 2. 1 DNA antisense strand acts as template so free RNA nucleotides can pair up to complimentary base pairs 3. new H bonds formed between template strand and free RNA nucleotides 4. RNA polymerase joins adjacent free nucleotides together by forming phosphodiester bonds. 5. Pre mRNA is spliced to remove introns and join extrons 6. mature mRNA leaves nucleus.
49
In translation what is used to determine the amino acid sequence of a polypeptide?
the nucleotide sequence of mRNA is used to determine amino acid sequence of a polypeptide.
50
Compare tRNA anticodon to mRNA codon for 1 amino acid
tRNA anticodon is complimentary to mRNA codon
51
Outline Translation steps
1. the small subunit of a ribosome binds to mRNA at the start codon 2. a tRNA molecule with an anticodon complimentary to the start codon attaches and is held together by H bonds between complementary base pairs of mRNA and tRNA) 3. many amino acids are coded for which are joined by peptide bonds 4. When stop codon is reached, polypeptide chain is released.
52
What is a frameshift?
where encoded amino acid sequence is altered following a mutation
53
What is base deletion, base insertion and base substitution?
Base deletion is 1 nucleotide lost from the sequence Base insertion is 1 nucleotide added to sequence Base substitution is when 1 nucleotide is used in place of another
54
What does base deletion and base insertion result in?
A frameshift
55
What is a point mutation?
when a base substitution affects one base triplet and the single amino acid it encodes
56
How does someone get sickle cell anaemia?
1. a point mutation in the gene encoding the beta globulin chains of haemoglobin 2. this results in GTC instead of GAG 3. RBC's become sickle cell shaped so carry oxygen less efficiently

Biology (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions