3.1 Biological molecules - water, ATP and inorganic ions Flashcards
what percentage of our bodies are made up of water?
60-70%
is water a polar or non polar molecule?
polar molecule
why is water a polar molecule?
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 type of bonding forms between different water molecules between the oxygen and a hydrogen atom?
hydrogen bonds
what are the 5 key properties of water?
1 - it is a metabolite (e.g. in condensation and hydrolysis reactions)
2 - an important solvent in reactions
3 - has a high heat capacity, and it buffers temperature
4 - has a large latent heat of vaporisation, providing a cooling effect with loss of water through evaporation
5 - has strong cohesion between water molecules; this supports water columns and provides surface tension
what are examples of reactions is water involved in?
photosynthesis, hydrolysis, and condensation reactions
what percentage of the plasma in the blood and the cytoplasm in cells is largely composed of water?
approximately 90%
what does it mean by water being a good solvent?
many substances dissolve in it
polar molecules dissolve readily in water due to the fact water is polar
the slight positive charge on hydrogen atoms will attract any negative ions in solutes and the slight negative charge on the oxygen atoms of water will attract any positive ions in solutes
are polar water molecules hydrophobic or hydrophilic?
hydrophilic, meaning they are attracted to water
are non polar molecules such as lipids hydrophobic or hydrophilic?
hydrophobic- they are repelled by water
why is water having a high specific heat capacity useful to organisms?
the temperature of the water remains relatively stable, therefore, the 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
why is water having a high specific heat capacity important for enzymes?
enzymes do not denature or reduce activity with temperature
fluctuations
what does large latent heat of vaporisation mean?
a lot of energy is required to convert water in its liquid state to a gaseous state
why does water have a large latent heat of vaporisation?
due to the hydrogen bonds, as energy is needed to break the hydrogen bonds between water molecules to turn it into a gas
why is a large latent heat of vaporisation advantageous?
water provides a significant cooling effect e.g. humans sweating
What is ATP?
Adenosine Triphosphate, an immediate source of energy for biological processes.
ATP is crucial for metabolic reactions in cells.
What role do the three phosphate ions in ATP play?
They are significant in energy transfer.
The phosphate groups are inorganic and do not contain carbon.
What are the components of ATP?
- Adenine
- Ribose
- Three inorganic phosphate groups.
Adenine is a nitrogenous base, and ribose is a pentose sugar.
What is the symbol for inorganic phosphate?
Pi
‘P’ represents phosphate, and ‘i’ indicates inorganic.
How is ATP synthesized during respiration?
From ADP by the addition of an inorganic phosphate via a condensation reaction using ATP synthase.
ADP stands for adenosine diphosphate.
What enzyme is responsible for hydrolyzing ATP?
ATP hydrolase.
This reaction produces ADP and inorganic phosphate.
What is the reaction for ATP hydrolysis?
ATP + water -> ADP + Pi + energy.
This process releases a small amount of energy used in chemical reactions.
Fill in the blank: ATP is an immediate energy source because only one bond has to be __________ to release energy.
hydrolyzed.
This allows for quick energy release for biological processes.
What is cohesion in the context of water molecules?
Cohesion is the term used to describe water molecules ‘sticking’ together by hydrogen bonds.
What is the advantage of water cohesion in plants?
It allows water to move up the xylem as a continuous column, making it easier to draw up.
How does cohesion contribute to the surface tension of water?
Cohesion provides surface tension, enabling small invertebrates to move and live on the surface.
What is one habitat advantage provided by water’s surface tension?
It provides small invertebrates with a habitat away from predators within the water.
What is the polar nature of water?
Water is a polar molecule.
What type of bonds form between water molecules?
Hydrogen bonds.
What are the key properties resulting from water’s polar nature and hydrogen bonds? List any.
- Metabolite
- Large latent heat of vaporization
True or False: Cohesion contributes to the ability of certain organisms to live on the surface of water.
True
Fill in the blank: Water’s _______ allows it to form hydrogen bonds with itself.
polar nature
What is the immediate energy source for cells?
ATP
ATP (adenosine triphosphate) is the primary energy carrier in cells.
What is the process of adding an inorganic phosphate to a compound called?
Phosphorylation
Phosphorylation increases the reactivity of compounds.
What is released during the hydrolysis of ATP that can bond to other compounds?
Inorganic phosphate
This phosphate group can enhance the reactivity of compounds.
What is the role of glucose in relation to phosphorylation?
Glucose is phosphorylated to become more reactive
This occurs at the start of respiration.
List the five key properties of ATP that make it a suitable immediate source of energy.
- Releases energy in small, manageable amounts
- Small and soluble for easy transport
- Only one bond is hydrolyzed for immediate energy release
- Can transfer energy through phosphate groups
- Cannot pass out of the cell
These properties highlight ATP’s efficiency compared to glucose.
True or False: ATP can pass out of the cell.
False
ATP remains within the cell to ensure a constant supply of energy.
Fill in the blank: ATP releases energy in _______ amounts.
small, manageable
This prevents wasted energy and overheating of cells.
What happens to glucose during phosphorylation?
It becomes more reactive
This process is essential for the initial stages of respiration.
Which molecule can enable phosphorylation by transferring phosphate groups?
ATP
Glucose does not have phosphate groups to facilitate this process.
How does ATP compare to glucose in terms of energy release?
ATP releases energy immediately; glucose requires several bonds to be broken
This makes ATP more efficient for quick energy needs.
What is the significance of ATP being small and soluble?
It is easily transported around the cell
This allows ATP to provide energy for various chemical reactions.
What are inorganic ions?
Inorganic ions dissolve to form solutions found within the cytoplasm of cells and other body fluids.
Do all inorganic ions require the same concentration?
No, some inorganic ions are required in high concentrations, while others are required in very low concentrations.
What role do hydrogen ions play in biological systems?
They determine pH, which is linked to enzymes.
What is the function of iron ions in the body?
They are a component of haemoglobin, linked to the transport of oxygen.
What is the role of sodium ions?
Involved in co-transport, linked to the absorption of glucose and amino acids in the ileum.
What do phosphate ions contribute to?
They are a component of DNA and ATP, linked to nucleotides and nucleotide derivatives.
What is ATP?
A nucleotide derivative made of adenine, ribose, and 3 phosphate groups.
What is the immediate source of energy for a cell?
ATP.
What is phosphorylation?
The addition of an inorganic phosphate to a molecule, transferring energy to that molecule.
Fill in the blank: ATP is a _______ derivative.
nucleotide
True or False: Inorganic ions perform the same function regardless of their properties.
False
List the key inorganic ions and their functions.
- Hydrogen ions - determine pH
- Iron ions - transport oxygen
- Sodium ions - co-transport of glucose and amino acids
- Phosphate ions - component of DNA and ATP
What are inorganic ions?
Inorganic ions dissolve to form solutions found within the cytoplasm of cells and other body fluids.
Do all inorganic ions have the same concentration requirement?
No, some inorganic ions are required in high concentrations, whereas others are required in very low concentrations.
What is the role of hydrogen ions?
They determine pH (linked to enzymes).
What is the significance of iron ions?
They are a compound of haemoglobin (linked to the transport of oxygen).
What role do sodium ions play in the body?
They are involved in co-transport (linked to the absorption of glucose and amino acids in the ileum).
What is the function of phosphate ions?
They are a component of DNA and ATP (linked to nucleotides and nucleotide derivatives).
What are the components of ATP?
Adenine, ribose and 3 phosphate groups.
What is the immediate source of energy for a cell?
ATP.
What is phosphorylation?
The addition of an inorganic phosphate to a molecule, transferring energy to that molecule.
True or False: Inorganic ions perform the same function in biological systems.
False.
How does cholera affect the small intestine?
It releases toxins affecting chloride ion channels, lowering the water potential of the small intestine’s lumen causing diarrhoea.
How is glucose involved in respiration?
Glucose is phosphorylated in glycolysis.
What happens to ADP during oxidative phosphorylation?
ADP is phosphorylated to ATP.
What is required in the sliding filament theory of muscle contraction?
ATP.
What processes require ATP in relation to active transport?
Resting potential, co-transport in the phloem, absorption of glucose.
What is cohesion?
Cohesion is the term used to describe molecules ‘sticking’ together by hydrogen bonds.
What advantage does cohesion provide for water movement in plants?
Cohesion allows water to move up the xylem in a continuous column rather than individual molecules.
How does cohesion contribute to surface tension in water?
Cohesion provides surface tension, enabling small invertebrates to move and live on the surface.
What are the five key properties of water resulting from its polar nature and hydrogen bonds?
- Metabolite
- Solvent
- Strong cohesion
- High specific heat capacity
- Large latent heat of vaporisation
True or False: Water is a polar molecule.
True
What role does water play as a metabolite?
Water is involved in key reactions such as photosynthesis and respiration.
Fill in the blank: Water’s strong cohesion links to ______ in plants.
transpiration
Fill in the blank: Water being a good solvent links to ______ in plants and animals.
mass transport
What is the role of water in biological reactions?
Water is involved in many reactions, such as photosynthesis, hydrolysis, and condensation reactions.
What percentage of plasma in the blood and cytoplasm in cells is composed of water?
Approximately 90%.
Define ‘metabolite’.
A metabolite is a substance involved in metabolic processes.
What is hydrolysis?
A chemical reaction that involves the breaking down of compounds by the addition of water.
What does the term ‘hydrophilic’ refer to?
Substances that are attracted to water.
What are monosaccharides?
The simplest form of carbohydrates, consisting of single sugar molecules.
What is a solvent?
A substance that dissolves a solute, resulting in a solution.
True or False: Water is a good solvent for polar molecules.
True.
What causes polar molecules to dissolve readily in water?
The polar nature of water, where slight positive and negative charges attract opposite ions.
What are hydrophobic substances?
Substances that are repelled by water and cannot dissolve in it.
Give an example of a hydrophobic substance.
Lipids.
What advantage does water provide for transporting substances in organisms?
Essential polar substances dissolve in water, enabling easy transport through blood or xylem.
What is high specific heat capacity?
A lot of energy is required to raise the temperature of water due to hydrogen bonds
This property allows water to maintain stable temperatures in organisms.
What role do hydrogen bonds play in water’s high specific heat?
Hydrogen bonds require energy to break, which stabilizes temperature changes
This is crucial for maintaining enzyme activity in organisms.
What is denaturation in the context of enzymes?
The process where enzymes lose their functional shape due to temperature fluctuations
This can reduce enzyme activity.
What is the significance of water’s high latent heat of vaporization?
A lot of energy is needed to convert liquid water to gas, providing a cooling effect
This is beneficial for organisms, such as during sweating.
How does sweating illustrate the concept of latent heat of vaporization?
Sweating releases water on the skin, transferring heat energy to water during evaporation
This results in a cooling effect for the body.
What advantage does stable internal temperature provide for aquatic organisms?
It creates a stable environment for biological processes, preventing denaturation
This stability is essential for their survival.
Fill in the blank: The large latent heat of vaporization of water is due to _______.
hydrogen bonds
True or False: Water’s high specific heat capacity allows for significant temperature fluctuations in organisms.
False
List the key terms associated with the properties of water discussed.
- High specific heat capacity
- Hydrogen bonds
- Denature
- Evaporate
- Cooling effect
What percentage of the human body is water?
60-70%
What type of molecule is water?
Polar molecule
What causes the unevenly distributed charge in a water molecule?
The oxygen atom is slightly negative, and the hydrogen atoms are slightly positive
What symbol indicates a slightly positive/negative charge in a water molecule?
Delta (δ) symbol
What forms between different water molecules?
Hydrogen bonds
Fill in the blank: Water is a _______ in condensation and hydrolysis reactions.
metabolite
List two important roles of water in biological reactions.
- Important solvent in reactions
- Metabolite in condensation and hydrolysis reactions
What property of water allows it to buffer temperature?
High heat capacity
What is the significance of water’s large latent heat of vaporisation?
Provides a cooling effect with loss of water through evaporation
What does strong cohesion between water molecules support?
Water columns and provides surface tension
True or False: Water has a low specific heat capacity.
False
