Moduel 1 : Nucleic Acids Flashcards
(29 cards)
What is an inorganic ion?
An atom or compound with an electrical charge. An inorganic ions is one that doesn’t contain carbon.
What is an anion?
An atom that has gained electrons so has a negative charge.
What is a cation?
An atom that has lost electrons so has a positive charge.
What are five inorganic ions that play key roles in cellular processes?
- Hydrogen ions
- Iron ions
- Sodium ions
- Phosphate ions
- Calcium ions
What are the role of Hydrogen ions in cellular processes?
They determine the pH of a solution. There is an inverse relationship between the pH value and the hydrogen ion concentration. The more hydrogen ions present the lower the pH. In the body the pH has an approximate value of 7.4. Changes in pH affects enzyme structure, they become denatured.
What are the roles of iron ions in cellular processes?
There are two versions of this ion. Iron (II) ions also known as ferrous ions. Iron (III) ions also known as ferric ions. Iron (II) ions are found each of the four polypeptide chains of haemoglobin, which is responsible for transporting oxygen around the body. Iron (II) ions are also found in Myoglobin, which is found in muscles and has a similar function to Haemoglobin. Iron ions are also responsible for the transfers of electrons during respiration and photosynthesis, so they are key to the biological generation of energy.
What are the roles of Sodium ions in Cell processes?
Na+ is required for the transport of glucose and amino acids across cell-surface membranes.
Glucose and amino acid molecules can only enter cells (through carrier proteins) alongside Na+
• This process is known as co-transport
• First, Na+ is actively transported out of the epithelial cells that line the villi
• The Na+ concentration inside the epithelial cells is now lower than the Na+ concentration in the lumen of the small intestine
• Na+ now re-enters the cells (moving down the concentration gradient) through co-transport proteins on the surface membrane of the epithelial cells, allowing glucose and amino acids to enter at the same time.
What are the roles of phosphate ions in cellular processes?
PO 3- attaches to other molecules to form phosphate groups, which are an essential
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component of DNA, RNA and ATP
• In DNA and RNA, the phosphate groups allow individual nucleotides to join up (to form polynucleotides)
• In ATP, the bonds between phosphate groups store energy
• These phosphate groups can be easily attached or detached
• When the bonds between phosphate groups are broken, they release a large amount of energy, which can be used for cellular processes
• Phosphates are also found in phospholipids, which are key components of the phospholipid bilayer of cell membranes
What die DNA stand for?
DeoxyriboNucleic Acid
What does RNA stand for?
RiboNucleic Acid
What is nucleic acid?
They are found in all living cells. They are needed to build proteins. They are important information carrying molecules. They are polymers.
What is the role of DNA?
To store genetic information. It contains instructions for growth an development.
What is the role of RNA?
It transfers the genetic code found in DNA out of the nucleus and into ribosomes. Ribosomes are where proteins are produced - they ‘read’ RNA to make polypeptides in a process called translation.
What are the monomers of nucleic acids called?
Nucleotides
What builds up each nucleotide?
A pentose sugar (ribose or deoxyribose), nitrogen containing organic base, a phosphate inorganic group.
What are the four nitrogenous bases in DNA?
Adenine, Cytosine, Guanine and Thymine.
What are the four nitrogenous bases in RNA?
Adenine, Cytosine, Guanine and Uracil.
What shapes do nitrogenous bases exist in?
Purine and Pyrimidines.
What is a purine nitrogenous base?
They have a double ring structure. Adenine and Guanine.
What is a pyrimidine nitrogenous base?
Have a single ring structure. Cytosine, Thymine and Uracil.
By what reaction to nucleotides bond?
A condensation reaction between phosphate groups of one nucleotide and the pentose sugar of the next.
What is a phosphodiester bond?
It forms between two nucleotides. It gets its name as it has 2 ester bonds and a phosphate group. It makes a sugar phosphate backbone.
Why can DNA molecules be known as antiparallel?
It has two polynucleotide strands running in opposite directions.
What can the two strands of DNA be called and why?
The 3’ to 5’ stand and the 5’ to 3’ strand. Due to the fact that the phosphodiester bonds link the 5’ carbon of one sugar to the 3’ carbon of another.
