100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
Previously searched by you
Previously searched by you
logo
Summary Complete notes on AS/A level Biology B with the Pearson Edexcel exam board- Topics 1 to 3 CA$20.48   Add to cart
Quickly navigate to
Preview
  2.  
  3. PEARSON (PEARSON)
  4.  
  5. Biology
  6.  
  7. Topics 1-3

Summary

Summary Complete notes on AS/A level Biology B with the Pearson Edexcel exam board- Topics 1 to 3
 80 views  2 purchases
  • Course
  • Topics 1-3
  • Institution
  • PEARSON (PEARSON)
  • Book
  • Edexcel A level Biology B Student Book 2 ActiveBook

This includes the perfect and complete summary notes from Topics 1 to 3 for the Biology B AS/A level exam using the Pearson Edexcel exam board. These notes are written following the Pearson Edexcel Specification, including all the necessary requirements according to the specification. They also in...

[Show more]

Preview 2 out of 11  pages

Document information

  • No
  • Topics 1 to 3
  • November 7, 2022
  • 11
  • 2022/2023
  • Summary

Subjects

  • biology
  • biology b
  • biological molecules
  • cells
  • complete a level biolo
  • paper 1 advanced biochemistry
  • microbiology and genetics
  • viruses and reproduction of living things
  • classification and biodiversity

Connected book

book image

Book Title:

Author(s):

  • Edition:
  • ISBN:
  • Edition:

More summaries for

  • Complete notes on Topic 2 Biology- Pearson Edexcel
  • Complete notes on AS/A level Biology B Pearson Edexcel
  • Complete AS/A level Biology B Pearson Edexcel noted
All for this textbook (4)

Written for

  • A/AS Level
  • PEARSON (PEARSON)
  • Biology
  • Topics 1-3
All documents for this subject (4)

Seller

avatar-seller
CosimaMartinez1234

Content preview

Topic 1: Biological Molecules
1.1 Carbohydrates
- General formula: Cx(H2O)n
- Made up of elements; Carbon, Hydrogen, Oxygen
- Made up of sugar units called saccharides

1. Monosaccharides; Monomers of one sugar unit
- General formula: (CH2O)n - (n= from 3 to 7)
Triose sugars - Three carbon atoms (n=3)
(C3H6O3) - Mitochondria- broken down from glucose into triose sugars during respiration

Pentose sugars - Five carbon atoms (n=5)
(C5H10O5) - Ribose and deoxyribose
- Making genetic material- nucleic acids (DNA and RNA)




Hexose sugars - Six carbon atoms (n=6)
(C6H12O6) - Highly soluble in water
- Isomers; same chemical formula but different structure
1. Glucose; main substrate for respiration (cardiac tissues)
- Carbon atom always bonded to oxygen atom in a stable closed chain
- Isomers; a-glucose and B-glucose
- BUT in B-glucose; H and OH swap in C1
2. Galactose; production of glycolipids and glycoproteins
- Not as soluble
3. Fructose; sweet and very soluble
- Source of energy in respiration




Condensation Reactions Hydrolysis reactions

- Monosaccharides join to form disaccharides and - Disaccharides and polysaccharides split
polysaccharides - Water molecule is added to break glycosidic bond
- Formation of glycosidic bond - covalent bond - Used to digest polysaccharides in the gut (starch,
- One molecule of
water +
+H2O
+ formed/released
glycogen, cellulose
+H2O per bond



2. Disaccharides; Two monosaccharides
- Form 1,4-glycosidic bond (C-O-C)
Disaccharide Source Monosaccharide

Sucrose Stored in plants (sugar cane) a-glucose + fructose

Lactose Milk sugar a-glucose + B-glucose

Maltose Germinating seeds (barley) a-glucose + a-glucose

, 3. Polysaccharides; Chains of 11+ monosaccharide units
- Not sugars; do not contain the sweet taste

- Starch and Glycogen;
1. Form compact molecules; large numbers can be stored
2. Glycosidic bonds easily broken; rapid release of glucose for cellular respiration
3. Insoluble; do not cause osmotic water movements/change water potential of cell
4. Flexible
Starch - Plant storage of glucose
(plant) - Long chain of a-glucose units
- Mixture of two polysaccharides;
1. Amylose
- Helix shape
- Longer unbranched polymer of a-glucose molecules
- Joined by 1,4-glycosidic bonds
- Releases glucose slowly over a long period of time
2. Amylopectin
- Helix shape with branches
- Shorter branched polymer of a-glucose molecules
- Joined by 1,4 and branches with 1,6-glycosidic bonds
- Releases glucose rapidly- easily hydrolysed and digested

Glycogen - Animal storage of glucose
(animals - Branched chain of a-glucose units
and fungi) - Joined by 1,4 and branches with 1,6-glycosidic bonds
- Large surface area as it is very branched- contains many 1,6-glycosidic bonds
- Hydrolysed quickly as it forms many bonds- rapid release of energy

Cellulose - Plant structure- component of cell wall; gives strength and structural support
(plant) - Long, straight, unbranched chains of inverted B-glucose units

- Joined by inverted 1,4-glycosidic bonds
- Alternating unit inversion causes cross-linking; hydrogen bonds form between the partially positive
hydrogen atoms of the hydroxyl (-OH) group and the partially negatively oxygen atoms
- Hydrogen bonds hold the chain in strong, rigid threads; microfibrils- they increase tensile strength to
withstand osmotic pressure
- Insoluble
- Permeable
- Hard to digest


Test for reducing sugars; all monosaccharides and some disaccharides (maltose
and lactose)
- Benedict's solution; chemical test
- Contains copper(II) ions which are reduced to copper(I) ions when heated
- Change in colour; increasing concentration
(blue - green - yellow - orange - brick red)

Test for non reducing sugars (do not react with Benedict's solution); sucrose
- Heat sucrose with a few drops of hydrochloric acid to hydrolyse the
glycosidic bonds and allow it to cool
- Neutralise solution with sodium hydrogen carbonate- produces the
monosaccharide unit the sugar
- It will now give a positive Benedict's test

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

Quick and easy check-out

You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.

Focus on what matters

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller CosimaMartinez1234. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for CA$20.48. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

78600 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy study notes for 14 years now

Start selling

Recently viewed by you

Exam (elaborations) ·

(0)

LIST of Exam

CA$20.48  2x  sold
  • (0)
  Add to cart