Unity and Diversity. Water and Nucleic Acids SL, HL

why is waters polarity important

allows water to form h-bond and dissolve many substances, which are essential for its unique qualities and biochemical reactions

rna

mRNA	Messenger RNA	Carries the genetic code from DNA to the ribosome. Acts as the “instructions” for the protein sequence.
tRNA	Transfer RNA	Brings specific amino acids to the ribosome. Has an anticodon that pairs with mRNA codons to ensure correct amino acid order.
rRNA	Ribosomal RNA	Forms the core of the ribosome’s structure and catalyzes peptide bond formation (acts as a ribozyme).

biochemical reactions

chemical transformations that occur in living organisms

cellular processes

coordinated series of events occurring within cells that maintain life functions

why is waters role in cellular processes crucial

it is an active participant in biochemical reactions, making processes more efficient

water - irreplaceable solvent for life

it has a unique combination of properties: polarity, high heat and evaporation capacity, ability to dissolve substances

how does water help thermoregulation in organisms

water high specific capacity allows it to absorb and release heat, helping maintain stable internal temperatures

relationship between water and enzymatic reactions

water actively participates in such reactions making processes like hydrolysis and condensation easier and faster

eg of waters role in transport

oxygen dissolving in water in the bloodstream allows it to be carried the cells

water the universal solvent

water can dissolve a wide range of substances allowing molecules to interact and by chemical reactions to occur

prebiotic soup

a nutrient rich mixture of organic molecules dissolved in water, providing ideal conditions for chemical reactions and the emergence of the first cells

enzymatic reactions

processes where enzymes, acting as catalyst, accelerate chemical reactions by lowering the activation energy

cellular respiration

process where organisms break down organic compounds to release controlled energy in the form of ATP

impact of water on cellular respiration

positively influences the efficiency and effectiveness of the processes by

solvent properties of water

polar and ionic substances dissolve easily

cytoplasm is aqueous so metabolism can occur efficiently

transport - plants (xylem, phloem); animals - plasma

what is in plasma

NaCl, glucose, amino acids, 02 with hemoglobin, fats with lipoproteins

how how can our understanding of water shape the future of biology and medicine?

understanding its properties can lead to advancements in biological research, medical practices and space exploration

specific heat capacity

amount of heat a substance can absorb or release without undergoing significant temperature changes.

amount of energy required to change the temperature of a substance

how do h-bonds contribute to waters resistance to temp changes

large amounts of energy are required to break hydrogen bonds

hydrogen bonds versus covalent bonds

hydrogen bonds are weak intermolecular forces while covalent bonds are strong bonds formed by the sharing of electrons

homeostasis

the body’s self-regulating process of maintaining a stable internal environment to ensure optimal conditions for cellular processes

role of h-bonds for maintaining homeostasis in organisms

hydrogen bonds give water a high specific heat capacity which helps stabilise temperatures

surface tension

inward pull on water molecules and the surface due to h bonds, creating a surface that insects (eg. pond skaters) can walk on without sinking

soaps effect on surface tension

It disrupts hydrogen bonding reducing surface tension which can cause oxygen to sink

surface tension in ecosystems

create unique habitats for surface dwelling organisms and those just below the surface supporting biodiversity

intramolecular versus intermolecular bonding

intra occurs within a molecule, inter occurs between molecules

cohesion and adhesion benefit to plants

cohesion and adhesion enable plants to transport water and nutrients from roots to leaves, where photosynthesis occurs

Capillary action

The movement of water through narrow spaces even against gravity

soil textures effecton capillary action

find texture soils like they have smaller pores that enhance capillary action while coarse texture soils like sand soils have larger pores that reduce it

what moisture level in soil is capillary action most effective?

when soil is moderately moist

capillary action and waterlogged soil

gravity overpowered the adhesive and cohesive forces, limiting water movement

surface area of soil effect on capillary action

soils with a higher surface area exhibit stronger adhesive forces, enabling more water to be drawn upward

arid region

region of intense heat, dramatic temp fluctuations or severe lack of rainfall

importance of capillary action in arid regions

Distributes water throughout the soil making it accessible to plant roots

Cellulose role in capillary action

it is a hydrophilic material that forms hydrogen bonds with water allowing water to adhere to plant cell wall and spread through them

hydrophilic versus hydrophobic

hydrophilic attracts water through h-bonds. hydrophobic repells water because these molecules are non polar

how does capillary action maintain moist cell wall during transpiration?

adhesive forces between water and cellulose draw new water molecules from the xylem vessels to replace evaporated water

functions of moist cell walls in plants

carbon dioxide absorption

structural support

nutrient transport

cavitation

when xylem vessels become air filled

how does capillary action help refilling xylem vessels after cavitation

It draws water back into air filled vessels restoring wire functionality

why is understanding capillary action important for agriculture?

it helps with efficient irrigation, preventing water logging and improving soil texture for better water availability

how do plants transport water

plants use cohesion to overcome gravity and move fluids up

how does waters hhc benefit aquatic environments

helps maintain stable temperatures, providing a consistent environment for life processes

role of cohesion in xylem vessels

Cohesion assures that water molecules form an unbroken column from the roots to the leaves

cohesion

water molecules sticking together, the attraction between water molecules due to h bonding, allowing water to form droplets

adhesion

water molecules clinging (adhering) to other surfaces due to h bonding

importance of cohesion and adhesion to plants

vital for transpiration, allowing water to travel from roots and leaves against gravity

transpiration

process where plants lose water vapor from their aerial parts, primarily through tiny pores (stomata) on their leaves

metabolism

Chemical reactions occurring in an organism to maintain life, including catabolism and anabolism

catabolism versus anabolism

Breaking down molecules and building molecules

Water as a solvent in cells

dissolves ions and polar molecules creating an aqueous environment that allows enzymes, substrates and other molecules to interact

hydrolysis reaction vs condensation reaction

h- water breaks down complex molecules into simpler ones by adding water

c- building molecules with the removal of water

role of water in the transport of substances

water is the primary component of fluids like blood and lymph that transport nutrients, gases and waste products

what cause the polarity of a water molecule

unequal sharing of electrongs between oxygen and hydrogen atoms due to oxygens higher electronegativity

electronegativity

atoms ability to attract electrons in a bond

charge of oxygen atom vs hydrogen atom in water molecule

oxygen has slightly positive and hydrogen has slightly negative

h-bonds

weak intermolecular force that forms between slightly positive hydrogen atoms and a slightly negative atom in a neighbouring molecule

cohesion tension hypothesis

most supported theory that explain how water moves upward from root to leaf, through cohesion, adhesion and transpiration and xylem

importance of glucose bonding with water

allows glucose to be transported around the body by blood

cytosol, eg of hydrophylic use

jelly-like substance found within the cytoplasm of a cell composed of 80 % water. if its molecules were hydrophobic, water would not work as a medium for metabolism and reactions could not be carried out

significance of water in cellular metabolism

dissolves reactants and enzymes, nutrient transport

catabolic vs anabolic

catabolic reactions break down larger molecules into smaller ones, anabolic does vice versa

Importance of hydrogen bonds

h-bonds give water its unique properties such as high boiling point, surface tension, ability to dissolve substances

how does water provide buoyancy to aquatic organisms

waters density provides buoyancy, reducing the energy needed for organisms to float

buoyancy

An upward for supply to an object that is immersed in fluid. if the buoyant force is greater than the objects weight, it will float

viscosity

liquids resistance to flow determined by the internal friction between its molecules

eg. water has low viscosity, allowing it to flow easily

air vs water viscosity

waters viscosity is about 50 times greater

one adaption ringed seals use to overcome drag in water

streamlined body that reduces resistance while moving through water

impact of air low viscosity on the black floated loon

allows for relatively frictionless movement, but the loon must overcome air resistance during take off

water vs air thermal conductivity

waters is higher so it conducts heat away from the body more efficiently

how do ringed seals combat heat loss in water

they rely on thick blubber layers for insulation and use counter current heat exchange system in their blood vessels

waters specific heat capacity compared to airs

4.18 J/g°C4.18J/g°,1.01 J/g°C

what challenges do the terrestrial and aerial animals face due to airs low specific heat capacity?

allow rapid temperature changes, requiring animals to adapt to fluctuating temperatures

how does the black throated loon reduce heat loss while diving?

it has dense waterproof weathers that trap insulating air pockets

asteroids role in the origin of water on earth

Delivered water during the early solar system by carrying it within hydrated minerals

why is earth size significant for retaining water

It provides a gravitational advantage which allows gravity to pull water

what happens to water molecules on smaller planets like Mars

They have weaker gravity so water escapes into space

how does earths magnetic field contribute to water retention

shields the atmosphere from solar winds which could strip away molecules like water vapour

comet hypothesis in the origin of water

water-rich comets collided with earth supported by isotopic analysis of comets and earths water

asteroid hypothesis

water was delivered by carbonaceous chondrite asteroids during the late heavy bombardment period, supported by isotopic analysis of earths oceans and asteroids

solar nebula hypothesis

water was part of the dust and gas in the solar nebula from which earth formed

goldilock zone (habitable zone)

a region around a star where conditions are just right for liquid water to exist on a planets surface, due to a suitable temperature range (not too close, not too far from the sun)

how does gold support the hypothesis that water was brought to Earth by asteroids

since the earths crust contains a remarkable amount of gold, it is believed that gold was delivered by asteroids after the planets formed

extraterrestrial life

life outside the earth

why do scientist look for water when looking for extraterrestrial life

Without liquid water, the complex chemical processes required for life would not occur

how does a stars size and energy output affect the goldilocks zone

the more powerful a star, the farther out its Goldilocks Zone will be and the broader that zone will be This relationship is key to finding potentially habitable exoplanets

greenhouse gases influence on the goldilocks zone

greenhouse gases, such as co2, can trap heat and influence whether liquid water can exist

how do astronomers identify plants within the goldilocks zone

they use advanced telescopes to explore exoplanets

what evidence suggests that Mars may have had condition suitable for life?

features like ancient river beds and sub surface of ice indicate the presence of liquid water and its past

which icy moons are considered promising candidates in the search of life

europa (jupiter) and enceladus (saturn) due to their subsurface oceans

what other factors influence a planets ability to support life

a stable atmosphere, the presence of essential elements and protection from harmful radiation

what role did volcanic activity play in the solar nebula hypothesis

water molecules trapped in minerals were released through volcanic activity

deuterium to hydrogen ratio

isotopic measure used to compare the comet, asteroid and earths water composition

deuterium

colorless, odorless gas that forms stronger chemical bonds than regular hydrogen due to increased mass. 2^H

advantage of waters low viscosity to aquatic organisms

more efficient and agile movements

adaptation in ringed seals for buoyancy

their fat rich blubber, which is less dense than water, enhances buoyancy, helping them float effortlessly or dive with minimal effort

waters benefit for biological structures

contributes to the formation of cell membranes, impacts the folding of proteins surrounds DNA to support double helix

ionic bond

attraction between a positively charged and negatively charged ion

Covalent bond

shares one or more pair of electrons between atoms

DNA

deoxyribonucleic acid - the universal instruction manual that every living organism uses to build and maintain itself