Chemicals of Life - Nucleic Acids - Post 16 Biology (A Level, Pre-U, IB, AP Bio)
Summary
TLDRThis script introduces nucleic acids, comprising DNA, RNA, and ATP. DNA is a double-stranded molecule with a double helix structure, made of nucleotides containing a phosphate group, deoxyribose sugar, and nitrogenous bases (cytosine, thymine, adenine, guanine). The strands run antiparallel, with bases pairing complementarily (A-T, C-G). RNA is single-stranded, with ribose sugar and uracil instead of thymine. ATP, a nucleotide with adenine, ribose, and three phosphate groups, serves as the cell's energy currency, releasing energy upon bond breakage.
Takeaways
- 🧬 Nucleic acids are composed of nucleotides, which include a phosphate group, a pentose sugar, and a nitrogenous base.
- 🌟 DNA (Deoxyribonucleic acid) is a well-known nucleic acid made up of nucleotides with four different bases: adenine, thymine, cytosine, and guanine.
- 🔍 The DNA structure is a double helix, resembling a twisted ladder, with each strand being a polymer of nucleotides.
- 🔗 DNA nucleotides are linked by phosphodiester bonds, formed through condensation reactions that remove water.
- 🌐 DNA strands are antiparallel, with one strand running in the opposite direction to the other, facilitating base pairing.
- 🤝 Complementary base pairing in DNA involves adenine pairing with thymine and cytosine pairing with guanine.
- 🧵 RNA (Ribonucleic acid) is structurally similar to DNA but has three key differences: it's single-stranded, uses ribose instead of deoxyribose, and contains uracil instead of thymine.
- 🔋 ATP (Adenosine triphosphate) is a nucleotide that contains three phosphate groups and is crucial for cellular energy transfer.
- ⚡ Breaking the bond between the last two phosphates in ATP releases energy, which cells use for metabolic processes.
- 🔄 ATP is often referred to as the 'energy currency' of the cell, highlighting its role in providing energy for various cellular functions.
Q & A
What are nucleic acids composed of?
-Nucleic acids are composed of nucleotides, which consist of a phosphate group, a sugar (pentose), and a nitrogenous base.
What are the three types of nucleic acids mentioned in the script?
-The three types of nucleic acids mentioned are deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and adenosine triphosphate (ATP).
What is the structure of DNA?
-DNA has a double helix structure, which is like a twisted ladder, with each ladder rung being a pair of nucleotides.
What are the four different nucleotides that make up DNA?
-The four different nucleotides that make up DNA are adenine (A), thymine (T), cytosine (C), and guanine (G).
What is the sugar component of DNA nucleotides?
-The sugar component of DNA nucleotides is deoxyribose.
How are nucleotides linked together in DNA?
-Nucleotides are linked together in DNA by phosphodiester bonds, which are formed through condensation reactions that remove water.
What is the significance of the antiparallel arrangement of DNA strands?
-The antiparallel arrangement of DNA strands means that one strand runs in one direction and the other in the opposite direction, allowing for complementary base pairing.
What is complementary base pairing in DNA?
-Complementary base pairing in DNA is the specific pairing of nucleotide bases where adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G).
How does RNA differ from DNA?
-RNA differs from DNA in that it is single-stranded, it contains the sugar ribose instead of deoxyribose, and it contains uracil instead of thymine.
What is ATP and why is it important for cells?
-ATP, or adenosine triphosphate, is a nucleotide with adenine as its base, ribose as its sugar, and three phosphate groups. It is crucial for cells because breaking the bond between the last two phosphates releases energy that cells use for metabolic processes.
How many hydrogen bonds are there between adenine and thymine in DNA?
-There are two hydrogen bonds between adenine and thymine in DNA.
How many hydrogen bonds are there between cytosine and guanine in DNA?
-There are three hydrogen bonds between cytosine and guanine in DNA.
Outlines
🧬 Nucleic Acids: Structure and Components
This paragraph introduces nucleic acids, which are composed of nucleotides consisting of a phosphate group, a pentose sugar, and a nitrogenous base. The paragraph focuses on three key nucleic acid molecules: DNA, RNA, and ATP. DNA is highlighted as a double-stranded molecule with a double helix structure, where each strand is composed of nucleotides. The nucleotides in DNA are of four types, distinguished by their bases: adenine and guanine (purines), and cytosine and thymine (pyrimidines). The strands are antiparallel, with bases pairing through hydrogen bonds in a complementary manner (A with T and C with G). The paragraph also briefly mentions the structure of RNA, which differs from DNA in being single-stranded, having ribose as its sugar, and containing uracil instead of thymine. Lastly, ATP is introduced as a nucleotide with three phosphate groups, important for energy transfer within cells.
🔋 ATP: The Energy Currency of the Cell
The second paragraph delves into ATP, or adenosine triphosphate, which is a nucleotide with three phosphate groups. It explains that the hydrolysis of the bond between the last two phosphates releases energy, making ATP a crucial molecule for cellular energy needs. ATP is likened to the 'batteries' of the cell, powering various metabolic processes. The paragraph emphasizes the importance of ATP in cellular energy management.
Mindmap
Keywords
💡Nucleic Acids
💡Nucleotides
💡DNA (Deoxyribonucleic Acid)
💡RNA (Ribonucleic Acid)
💡ATP (Adenosine Triphosphate)
💡Pentose
💡Base Pairing
💡Phosphodiester Bond
💡Antiparallel
💡Polynucleotides
💡Complementary
Highlights
Nucleic acids are composed of nucleotides, which consist of a phosphate group, a pentose sugar, and a nitrogenous base.
DNA, RNA, and ATP are the three nucleic acid molecules that will be covered in the course.
DNA has a double helix structure, resembling a twisted ladder made of nucleotides.
Nucleotides in DNA are of four types, with cytosine and thymine being purines, and adenine and guanine being pyrimidines.
DNA is composed of two antiparallel strands, with the sugar deoxyribose indicating the 'D' in DNA.
The bases in DNA pair up through complementary base pairing, with A always pairing with T and C with G.
The direction of DNA strands is indicated by the terms five prime and three prime ends.
RNA is similar to DNA but differs in being single-stranded, having ribose instead of deoxyribose, and containing uracil instead of thymine.
ATP, or adenosine triphosphate, is a nucleotide with three phosphate groups and is crucial for cellular energy transfer.
The breaking of the bond between the last two phosphates in ATP releases energy for cellular metabolic processes.
Nucleotides are linked together by condensation reactions, forming phosphodiester bonds.
DNA's double helix is stabilized by hydrogen bonds between the base pairs.
The structure of RNA will be revisited in the course to explore its functions and role in the cell.
ATP is often referred to as the 'battery' of the cell due to its role in energy storage and release.
The significance of the double helix structure in DNA for genetic information storage and replication.
The importance of complementary base pairing in DNA for accurate replication and transcription.
The role of the five prime and three prime ends in DNA synthesis and processing.
The structural differences between DNA and RNA and their implications for their functions.
Transcripts
now the final group of biological
molecules are going to learn about in
this section are nucleic acids now
nucleic acids are made up of nucleotides
a nucleotide has three parts to it a
phosphate group a sugar which will be a
pentose five carbon sugar and a base
nitrogenous base which contains nitrogen
now there are three molecules that are
made up of these nucleotides that you're
going to be coming across in the course
these include deoxyribonucleic acid DNA
ribonucleic acid RNA and adenosine
triphosphate or ATP we'll look at DNA
first as it's probably the one you've
heard about most so DNA structure may
look very complicated but actually it's
quite simple if you break it down into
its component parts it has this special
shape this double helix as it's called
which is basically a ladder that's been
twisted up and each ladder is a strand
of DNA it's a polymer made up of many
repeating units called nucleotides the
nucleotides come in four different
versions and when you join nucleotides
together in a long chain to make a
strand we call them poly nucleotides or
this is an example of a nucleic acid as
I've already mentioned nucleotides have
three parts so the nucleotides that make
up DNA contain the phosphate group like
we said they contain sugar and in this
case the sugar is deoxyribose which is
where DNA the D part of DNA comes from
deoxyribonucleic acid and the base as I
said there are four different
nucleotides that make up DNA and those
very base because of these bases the
four bases that you can have our
cytosine thymine which are both examples
of purine bases and then there are two
other ones adenine and guanine which for
example of pyrimidine bases
each nucleotide is linked to the next
nucleotide by a condensation reaction
just like condensation reactions that
we've seen before this is a reaction to
make a bond covalent bond which will
remove water the bond formed in this
case is called a phosphodiester bond so
when you join lots of nucleotides
together with lots of condensation
reactions and make these phosphodiester
bonds we end up with a poly nucleotide
or a nucleic acid and that makes one
strand of the DNA but to make DNA it's a
double-stranded molecule we need to
another strand we need an opposing
strand and the Strand is actually
arranged in the opposite direction it's
what we call anti parallel so one goes
in one direction the other strand goes
in the opposite direction the bases
always pair up between these two strands
in the same way a purine base will
always pair with a pyrimidine base this
means that a always pairs with T and C
always pairs with G it's what we call
complementary base pairing in order to
explain the direction of the Strand we
use the terms five prime and three prime
the end with the spare phosphate
sticking out is the five prime end the
two strands are joined together by
hydrogen bonds between the base pairs
there are two hydrogen bonds between a
and T and there are three hydrogen bonds
between C and G so the second nucleic
acid we're gonna look at is called RNA
and it's actually very similar to DNA
apart from three major differences RNA
is a single stranded molecule it's not
double stranded like DNA RNA it has a
different sugar in its nucleotides in
DNA is deoxyribose but in RNA it's
ribose RNA does not contain the base
thymine it contains uracil instead so
while in DNA you had adenine thymine
guanine and cytosine in RNA you have
adenine guanine and cytosine but then
you have uracil instead of thymine we're
coming back in the course many times to
look at RNA and it's
functions and how it's used by cells but
for now we're just going to look at the
structure of it the final nucleic acids
we're gonna learn about is ATP again
we're going to learn about ATP a lot
more when you look at respiration and
the process of respiration and how
energy is used in the cell ATP stands
for adenosine triphosphate and it is a
nucleotide which contains the base
adenine it's got the sugar ribose and
instead of having one phosphate group
actually three phosphate groups attached
now this is important because if you
break the covalent bond between the last
two phosphates it releases a little bit
of energy and this is why ATP are like
the batteries for a cell the cell will
use ATP and break that bond to release
the energy to for all its metabolic
processes
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