Flashcards in More biological molecules Deck (50):
What is the function of DNA?
It stores genetic information
What are ribosomes made up of?
RNA and proteins
Name the monomer of DNA and RNA
What join together to form polynucleotide stands?
What kind of bond, present in a polynucleic chain, consists of two ester bonds and a phosphate group
Describe 3 differences between DNA and RNA
DNA is double stranded, RNA is single stranded
DNA contains thymine, RNA replaces it with uracil
RNA is relatively short compared to DNA
What caused many scientists to doubt that DNA carried the genetic code
DNA has a relatively simple chemical composition
DNA and RNA are both types of what acid?
What is the full name for DNA
What is the full name of RNA
What is the function of RNA
To transfer genetic information from the DNA to the ribosomes
What is the function of ribosomes
They read RNA to make polypeptides
What are the three components in DNA structure
A phosphate group
A nitrogen containing base
A deoxyribose sugar
DNA is copied by semi-conservative replication of DNA. What is meant by this?
It's where half of the new strands of DNA are from the original molecule of DNA
Name two enzymes involved in DNA replication
Describe the first stage of DNA replication, in which two strands of DNA are separated
DNA helicase breaks the hydrogen bonds between the base pairs on the two polynucleotide DNA strands. This makes the helix unwind to form two single strands
Describe the second stage of DNA replication, where the single strands of DNA act as templates
Free floating DNA nucleotides are attracted to their complementary exposed bases in each original template strand
Name two examples of processes that plants need energy for
Name two examples of processes that animals need energy for
What does ATP stand for?
What is the process called in which plants and animals release energy from glucose
A cell can't get its energy directly from glucose therefore what happens?
The energy released from glucose is used to make ATP
Describe the structure of ATP
Nitrogen containing base, adenine
3 phosphate groups
Why is ATP known as a nucleotide derivative
Because it's a modified form of a nucleotide
Where is the energy in ATP stored?
In high energy bonds between the phosphate group
When energy is needed by a cell, what happens to ATP?
It gets broken down into ADP and Pi
How is energy released during the hydrolysis of ATP?
A phosphate bond is broken, releasing the stored energy
What enzyme catalysis the breakdown of ATP?
ATP hydrolysis can be coupled to other energy requiring reactions in the cell, what does this mean?
That energy released can be used directly to make the coupled reaction happen
How can inorganic phosphate (Pi) be used?
Added to another compound, which makes the compound more reactive
What reaction happens when ATP is resynthesised from ADP and Pi?
Name two examples of processes where ATP resynthesis occurs
What enzyme catalysed ATP resynthesis
Name 4 important functions of water
- it is a metabolite
- it is a solvent
- water molecules are very cohesive
- it helps with temperature control
Is water a polar or non-polar molecule?
What are hydrogen bonds?
Between slightly positively charged hydrogen atom in one molecule and a slightly negatively charged atom in another molecule
Name 2 reactions that water is involved in
Why is water classed as a polar molecule?
Because it has a slight positive charge on one side and a slight negative charge on the other
What is a metabolite?
A substance involved in metabolic reactions
What makes water useful as a solvent?
What is cohesion?
The attraction of two molecules of the same type
Why is water being a good solvent useful for living organisms?
It means they can take up useful substances dissolved in water and these can be transported around their body
In terms of its hydrogen bonds, when does water evaporate
When the hydrogen bonds holding the water molecules together are broken
What are ions?
An atom that has an electric charge
What is an atom with a positive charge called?
Give an example of a cation
What is an ion with a negative charge called?
Give an example of an anion
What is an inorganic ion
An ion that doesn't contain carbon