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 DNA - the code of life; and RNA: Matric Life Sciences $2.80
Add to cart
Quickly navigate to
Preview
  2.  
  3. Kingsmead College
  4.  
  5. Life Sciences Matric: IEB

Summary

Summary DNA - the code of life; and RNA: Matric Life Sciences

1 review
 0 purchase
  • Course
  • Life Sciences Matric: IEB
  • Institution
  • Kingsmead College

A concise, bullet-pointed summary on Nucleic Acids. Covers strictly what you need to know for all tests and assessments (as dictated by the SAGS guidelines). Includes annotated diagrams and images to illustrate points mentioned, as well as additional research, helpful when understanding the work

Preview 2 out of 11  pages

Document information

  • October 16, 2020
  • 11
  • 2020/2021
  • Summary

Subjects

  • nucleic acids
  • life sciences
  • matriculates syllabus

Written for

  • Kingsmead College
  • Life Sciences Matric: IEB
All documents for this subject (9)

1  review

review-writer-avatar

By: Ora123 • 2 year ago

Seller

avatar-seller
chloevanbeukering

Reviews received

Content preview

Chloë van Beukering Life Sciences Notes 2020


Nucleic Acids

• When a cell is dividing, its chromosomes become visible
• Analysis of the chromatin reveals that it is made of two major components:
• Deoxyribonucleic acid (DNA)
• The DNA is the molecule of heredity within whose structure is coded the information
of inheritance and the information for controlling the cell
• Proteins, called histones, that stabilise the DNA molecules

Chromosomes

• Each chromosome contains one very long DNA molecule that, when unravelled, would
measure about 4.8 cm in length
• The total length of DNA in the nucleus of one single human cell has been estimated to
be about 2.2 m
• The DNA is intricately folded and tightly bound around histones
• For most of the cell cycle, DNA molecules are in very long strands called chromatin, but
prior to cell division, the chromatin condenses
• This replicated DNA molecule, in its now condensed form, is now referred to as a
chromosome
• But, remember, there are two copies attached to each other until nuclear division occurs
• Each of the two copies of a chromosome are designated as a chromatid and they are
physically linked together at a point on the chromosome called the centromere

Nucleic Acids

• Nucleic acids are molecules that were originally thought to occur only in the nucleus

Two types of nucleic acids found in cells:
1. Deoxyribonucleic acid (DNA)
2. Ribonucleic acid (RNA)

• Both of these molecules are long, chain like structures built up from repeating similar
building blocks
• Both are thus, polymers
• Polymer: long chain of similar units joined end-to-end with each other
• Each unit of a polymer is called a monomer (building block)
• In a nucleic acid, the monomers are called nucleotides

Nucleotide consists of three units bonded together:
1. A sugar molecule (ribose or deoxyribose)
- Deoxyribonucleic acid had nucleotides in which the sugar is deoxyribose, while
ribonucleic acid contains the sugar ribose
2. A phosphate group
3. A nitrogenous base

1 of 11

, Chloë van Beukering Life Sciences Notes 2020




Deoxyribonucleic Acid (DNA)

• In 1953, the scientists James Watson and Frances Crick published the first description of
the structure of DNA based on a model they constructed mainly from experimental
work done by other scientists, including Rosalind Franklin
• DNA is a macromolecule / polymer that provides the template for making the cells
proteins, called the genetic code
• Most of the DNA in a eukaryotic cell is found in the nucleus but there is also DNA in
mitochondria (mtDNA) and chloroplasts

DNA has 2 characteristics:
1. It is a store of genetic information
2. It can copy itself exactly, time after time (called DNA replication)

Each nucleotide in DNA can contain any of four nitrogenous bases:
• A = adenine
• G = guanine
• C = cytosine
• T = thymine

• Within each nucleotide, the nitrogenous base is joined to the deoxyribose sugar and
the phosphate group is attached to the deoxyribose sugar
• Humans have 23 pairs or 46 chromosomes
• These chromosomes are further broken
down into smaller pieces of DNA called
genes, which make up coding DNA for
providing the template for making proteins
• Each DNA molecule consists of two
strands of nucleotides, bonded together
in the middle by weak hydrogen bonds
between pairs of nitrogenous bases
• Adenine can only bond with thymine
• Guanine can only bond with cytosine
• This is the complementary base pairing
rule

• The sides of the double stranded, ladder-like structure are formed by alternating sugar-
phosphate units, while the base pairs form the cross bridges like the rungs on a ladder

2 of 11

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 chloevanbeukering. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for $2.80. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

69988 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy study notes for 15 years now

Start selling
$2.80
  • (1)
Add to cart
Added