ATP, Inorganic Ions And Water Flashcards
What is energy required for in all organisms
In anabolic reactions – building larger molecules from smaller molecules
To move substances across the cell membrane (active transport) or to move substances within the cell
In animals, energy is required:
For muscle contraction – to coordinate movement at the whole-organism level
In the conduction of nerve impulses, as well as many other cellular processes
What does ATP stand for and what does it do?
ATP or Adenosine Tri Phosphate, is an immediate source of energy for biological processes. Metabolic reactions in cells must have a constant, steady supply of ATP.
What is ATP?
ATP is another type of nucleic acid and hence it is structurally very similar to the nucleotides that make up DNA and RNA
It is a phosphorylated nucleotide
ATP is described as a universal energy currency
Universal: It is used in all organisms
Currency: it can be used for different purposes (reactions) and is reused countless times
What can the nucleotide adenosine combine with?
Adenosine (a nucleoside) can be combined with one, two or three phosphate groups
One phosphate group = adenosine monophosphate (AMP)
Two phosphate groups = adenosine diphosphate (ADP)
Three phosphate groups = adenosine triphosphate (ATP)
What type of molecule is ATP
ATP is a small and soluble molecule that provides a short-term store of chemical energy that cells can use to do work
It is vital in linking energy-requiring and energy-yielding reactions
Why does atp play a significant role in energy transfer
ATP contains three phosphate ions that play a significant role in energy transfer and this biological molecule is essential to metabolism, which is all the chemical reactions that take place in a cell.
The energy released by ADP
breaking one of the bonds between the inorganic phosphate groups in a hydrolysis reaction, a small amount of energy is released to the surroundings, which can be used in chemical reactions.
This is why ATP is an immediate energy source- only one bond has to be hydrolysed to release energy.
ATP can also transfer energy to different compounds. The inorganic phosphate released during the hydrolysis of ATP can be bonded onto different compounds to make them more reactive. This is known as phosphorylation, and this happens to glucose at the start of respiration to make it more reactive.
The products of the hydrolysis of atp
Hydrolysis of ATP to adenosine diphosphate (ADP) and an inorganic phosphate group (Pi) is catalysed by the enzyme ATP hydrolase sometimes called ‘ATPase’
The hydrolysis of ATP can be coupled to energy-requiring reactions within cells such as:
The active transport of ions up a concentration gradient
Enzyme controlled reactions that require energy
Muscle contraction and muscle fibre movement
What is the other product of the hydrolysis of ATP other than ADP?
The inorganic phosphate released during the hydrolysis of ATP can be used to phosphorylate other compounds, often making them more reactive
How is atp synthesised
Atp is made during respiration from ADP, adenosine diphosphate, by the addition of an inorganic phosphate via a condensation reaction and using the enzyme ATP synthase.
Types of ATP synthesis
Types of ATP synthesis
ATP is made during the reactions of respiration and photosynthesis
All of an animal’s ATP comes from respiration
ATP can be made in two different ways:
Substrate-linked phosphorylation (occurs in the glycolysis stage of respiration)
Chemiosmosis (occurs in the electron transport chain stage of respiration)
Why is there a separation of charge in water?
This separation of charge due to the electrons in the covalent bonds being unevenly shared is called a dipole. When a molecule has one end that is negatively charged and one end that is positively charged it is also a polar molecule
Water is a polar molecule
What properties of water molecules do hydrogen bonds contribute to
An excellent solvent – many substances can dissolve in water
A relatively high specific heat capacity
A relatively high latent heat of vaporisation
Water is less dense when a solid
Water has high surface tension and cohesion
It acts as a reagent
Hydrogen bonds in water molecules
Hydrogen bonds form between water molecules
As a result of the polarity of water hydrogen bonds form between the positive and negatively charged regions of adjacent water molecules
Hydrogen bonds are weak, when there are few, so they are constantly breaking and reforming. However when there are large numbers present they form a strong structure
Water as a solvent
charged molecules dissolve in water due to the fact water is dipolar.
The slight positive charge on hydrogen atoms will attract any negative ions solutes and the slight negative charge on the oxygen atoms of water will attract any positive ions in solutes.
These polar molecules are often described as hydrophilic, meaning they are attracted to water.
Non-polar molecules, such as lipids, cannot dissolve in water and are therefore described as hydrophobic- they are repelled by water.
What is specific heat capacity
Specific heat capacity is a measure of the energy required to raise the temperature of 1 kg of a substance by 1oC
Why does water have a high specific heat capacity
The high specific heat capacity is due to the many hydrogen bonds present in water. It takes a lot of thermal energy to break these bonds and a lot of energy to build them, thus the temperature of water does not fluctuate greatly
Water has a high specific heat capacity of 4200 J / Kg oC
What is the advantage for living organisms that water has a high specific heat capacity?
is useful to organisms as it means the temperature of water remains relatively stable, even if the surrounding temperature fluctuates significantly.
Therefore, internal temperatures of plants and animals should remain relatively constant despite the outside temperature, due to the fact a large proportion of the organism is water.
is important so that enzyme do not denature or reduce in activity with temperature fluctuations.
The role of water in the blood plasma
helping to maintain a fairly constant temperature
As blood passes through more active (‘warmer’) regions of the body, heat energy is absorbed but the temperature remains fairly constant
Water in tissue fluid also plays an important regulatory role in maintaining a constant body temperature
Adavntage of waters high latent heat of vapourisation
is advantageous to organisms as it means that water provides a significant cooling effect. For example, when humans sweat they release water onto their skin.
Large amounts of heat energy from the skin is transferred to the water to evaporate it, and therefore removing a lot of heat and cooling the organism.
What is cohesion
Hydrogen bonds between water molecules allows for strong cohesion between water molecules
Cohesion is the term used to describe water molecules ‘sticking’ together by hydrogen bonds.
Due to water molecules sticking together, when water moves up the xylem in plants due to transpiration it is as a continuous column of water. This is advantageous as it is easier to draw up a column rather than individual molecules.
Cohesion and surface tension
Cohesion also provides surface tension to water.
This enables small invertebrates to move and live on the surface, providing them a habitat away from predators within water.
these hydrogen bonds occur between the top layer of water molecules to create a sort of film on the body of water (this is what allows insects such as pond skaters to float)
What is adhesion
Water is also able to hydrogen bond to other molecules, such as cellulose, which is known as adhesion
This also enables water to move up the xylem due to transpiration
What is an ion
An ion is an atom (or sometimes a group of atoms) that has an electrical charge
An ion that has a +ve charge is known as a cation
An ion that has a -ve charge is known as an anion
What is an inorganic ion
An inorganic ion is an ion that does not contain carbon
Inorganic ions play an important role in many essential cellular processes
When do inorganic ions occur
Inorganic ions occur in solution in the cytoplasm and body fluids of organisms
Some occur in high concentrations and others in very low concentrations
The concentration of certain ions can fluctuate and can be used in cell signalling and neuronal transmission
Hydrogen ions (H+)
Hydrogen ions are protons
The concentration of H+ in a solution determines the pH
There is an inverse relationship between the pH value and the hydrogen ion concentration
The more H+ ions present, the lower the pH (the more acidic the solution)
The fewer H+ ions present, the higher the pH (the more alkaline the solution)
Why is the concentration of (H+) ions important for enzyme controlled reactions.
The maintenance of this normal pH is essential for many of the metabolic processes that take place within cells
Changes in pH can affect enzyme structure
For example, abnormal levels of hydrogen ions can interact with the side-chains of amino acids and change the secondary and tertiary structures of the proteins that make up enzymes
This can cause denaturation of enzymes
Why are iron ions essential for binding oxygen
Haemoglobin is the large protein in red blood cells that is responsible for transporting oxygen around the body
Haemoglobin is made up of four polypeptide chains that each contain one Fe2+
This Fe2+ is a key component in haemoglobin as it binds to oxygen
Myoglobin in muscles functions in a similar way (it is an oxygen-binding protein) but is only made up of one polypeptide chain (containing one Fe2+)
The different versions of iron ions
There are actually two versions of iron ions (known as oxidation states)
Iron (II) ions, also known as ferrous ions (Fe2+)
Iron (III) ions, also known as ferric ions (Fe3+)
How are iron ions essential for the transfer of electrons
Iron ions are an essential component of cytochromes (that are themselves a component of electron transport chains)
Cytochrome c contains an iron ion that is essential to its function
During the electron transport process, this iron ion switches between the Fe3+ and Fe2+ oxidation states, which allows for electrons to be accepted and donated
What roles does the Na+ ion have?
Na+ is required for the transport of glucose and amino acids across cell-surface membranes (e.g. in the small intestine)
Na+ is also required for the transmission of nerve impulses, muscle contraction and regulating fluid in the body
Na+ role in co-transport
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
Phosphate Ions PO43- as essential components 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
Where else are phosphate ions found
Phosphates are also found in phospholipids, which are key components of the phospholipid bilayer of cell membranes
Ca2+ being essential in the movement of organisms:
Ca2+ is essential in the movement of organisms:
In synapses, calcium ions regulate the transmission of impulses from neurone to neurone
Ca2+ also stimulating muscle contraction
When an impulse reaches a muscle fibre, Ca2+ is released from the sarcoplasmic reticulum
This Ca2+ binds to troponin C, removing the tropomyosin from myosin-binding sites on actin
This allows actin-myosin cross-bridges to form when the muscle fibre contracts
What can Ca2+ ions help regulate
protein channels, which affects the permeability of cell membranes
Why are Ca2+ ions these ions key regulators in many biological reactions
Many enzymes are activated by Ca2+
Potassium ions K+
- important to generate nerve impulses, muscle contraction and regulating fluid balance in the body
- activating essential enzymes needed for photosynthesis and plant cells.
Hydrogen ions (H+)
Affects PH of substances (more conc = more acidid)
Also important for photosynthesis reaction that oocur in thylkaloid membranes inside chloroplasts
Ammonium (NH4+)
Absorbed from the soil by plants and is an important source of nitrogen (which is then used to make eg amino acids nucleic)
Hydrogen carbonate (HCO3-)
Acts as a buffer which helps maintain the PH of blood
Chloride (Cl-)
Involved in the chloride shift which helps maintain the ph of blood during gas exchange
Acts as a cofactor for the enxyme amylase
Involves in some nerve pulses
Hydroxide (OH-)
Affects ph pf substances (more concentrated = more alkali)
Explain 5 properties of water that is useful in living organism
A metabolite in condensation/hydrolysis/ photosynthesis/respiration; A solvent so (metabolic) reactions can occur
A solvent so allowing transport of substances;
High (specific) heat capacity so buffers changes in temperature;
Large latent heat of vaporisation so provides a cooling effect (through evaporation);
Cohesion (between water molecules) so supports columns of water (in plants);
Cohesion (between water molecules) so produces surface tension supporting (small) organisms;
State and explain property of water that can help buffer changes in temperature
High specific heat capacity
Can gain loss a lot of heat / energy without changing the state
What is atp compromised of
Adenine a nitrogenous base (meaning a base that contains nitrogen)
• Ribose (a pentose sugar)
• Three inorganic phosphate groups.
Water as a metabolite
Water in involved in may reactions, such as photosynthesis, hydrolysis and condensation reactions.
This is one reason why it is essential that approximately 90% of the plasma in blood is water and the cytoplasm in cells is largely composed of water.
Properties of ATP - releasing energy in a small manageble way
means that cells do not over heat from wasted heat energy and cells are less likely to run out of resources. In comparison to glucose, this would release large amounts of energy that could result in wasted energy.
ATP properties - small and solunle
transported around the cell.
ATP can move around the cytoplasm with ease to provide energy for chemical reactions within the cell. This is a property ATP has in common with glucose
Atp properties - only one bond is hydrolysed to release energy
is why energy release is immediate. Glucose would need several oonds to be bronch down to reicise ans energy.
Atp properties - can transfer enetrgy
It can transfer energy to another molecule by transferring one of its phosphate groups.
ATP can enable phosphorylation, making other compounds more reactive. Glucose cannot do this, as it does not contain phosphate groups.
Atp properties - cant pass out the cell
can’t pass out of the cell, the cell always has an immediate supply of energy.
ATP cannot leave the cell, where as glucose can. This means that all cells have a constant supply of ATP or ADP +Pi, but a cell can run out of giucose
What type of molecule is a water molecule
Water is a dipolar molecule (di meaning two and polar referring to charges). Water has an unevenly distributed charge due to the fact that the oxygen atom is slightly negative, and the hydrogen atoms are slightly positive.
What are the five key properties of water
It is a metabolite (e.g. in condensation and hydrolysis reactions).
An important solvent in reactions.
Has a high heat capacity, it buffers temperature.
Has a large latent heat of vaporisation, providing a cooling effect with loss of water through evaporation.
Has strong cohesion between water molecules; this supports water columns and provides surface tension
What does it mean when water has a large latent heat of vapourisation
This means that a lot of energy is required to convert water in its liquid state to a gaseous state. This is due to the hydrogen bonds, as energy is needed to break the hydrogen bonds between water molecules to turn it into a gas.
