Water and reactions Flashcards
% of water in lungs, brain, fat tissue, and bones
Lungs are about 90% water → bc lungs get gasses in and out of body
Brain is about 70% water
Fat tissue is about 25% water - fat + water are opposites
Bones have just over 20% water
functions of water in the body
Helps control body temperature → sweat evaporative cooling
Keeps eyeballs moist
Lubricates joints → synovial fluid
Shock absorber → lubrication for joints
Acts as universal solvent
except for fatty things
Water has many functions in the body
When you’re hot, the body sweats to cool you down
Also, the blood can either be shunted to the surface or to the core to cool or warm the body
The eyeballs needed to be moist or they would get irritated
Joints need to be lubricated or they would grind and prevent smooth movement
Cerebral and spinal fluid absorb the impact and prevent damage to the brain and the spinal cord
Everything dissolves in water
properties of water gr 11 chem
Water is colourless, tasteless, and odourless
Water can exist as a solid, liquid, or gas
Water has polar covalent bonds and an asymmetrical structure
This makes water molecules polar
O have neg diapoles
helps water bond to itself and to others
works with other/dissolves other substances that are polar
Properties of water
Cohesion
unit that sticks together, sticks well to itself
Water molecules attracting other water molecules
High surface tension
Used by plants to suck up water from ground
Insects walk across water
Allows water droplets to form
Properties of water
Adhesion
Water forms bonds with other polar molecules
sticking to other things → other polar molecules
In plants water sticks to xylem and is able to go up against gravity
Properties of water
Less Dense as a Solid
As water freezes it expands to form a lattice of V-shaped molecules
Helps aquatic life stay in their habitat despite being cold outside
Provides habitat for arctic animals
Properties of water
High Specific Heat
Large amounts of heat need to heat water
regulation of body temperature
Helps aquatic life stay in their habitat despite being cold outside
Provides habitat for arctic animals
Properties of water
High Heat of Vaporization
Large amounts of heat needed before water turns to gas
Sweating and panting
Cooling of our body
Properties of water
Universal Solvent
Ability to dissolve a large range of solutes/compounds
Transport nutrients throughout body
Bathes our cells (aqueous)
Get rid of waste
Water Clings
Explain the two properties of water that make this happen
Collectively, hydrogen bonds hold water molecules together, a phenomenon called cohesion
Cohesion helps the transport of water against gravity in plants
Adhesion is an attraction between different substances, for example, between water and plant cell walls
Solid water is less dense
explain why
Ice floats in liquid water because hydrogen bonds in ice are more “ordered,” making ice less dense
Water reaches its greatest density at 4°C
If ice sank, all bodies of water would eventually freeze solid, making life impossible on Earth
High specific heat
energy required to heat?
- the specific heat of a substance is the amount of heat that must be absorbed or lost for 1g of that substance to change its temperature by 1C
- the specific heat of water is 1cal/g/C
- water resists changing its temperature because of its high specific heat
1 cal is the energy required to heat one gram of water by 1 degree
homeostasis
Evaporative cooling
Evaporation is transformation of a substance from liquid to gas
As a liquid evaporates, a process called evaporative cooling
Evaporative cooling of water helps stablize temperatures in organisms and bodies of water
Water is the Universal Solvent
Solution, solvent, solute, and an aqueous solution definitions
- A solution is a liquid that is a homogeneous mixture of substances
- A solvent is the dissolving agent of a solution
- The solute is the substance that is dissolved
- An aqueous solution is one in which water is the solvent
Why is water a universal solvent?
- Water is a versatile solvent due to its polarity, which allows it to form hydrogen bonds easily
- When an ionic compound is dissolved in water, each ion is surrounded by a sphere of water molecules called a hydration shell
- needs polar properties to dissociate into the water (ions)
Van der Waals Forces
London Forces:
Exist between all molecules and atoms
Dipole-Dipole Forces
Hold polar molecules together
δ+ attracts δ- side of other molecules
Hydrogen Bonds
Electropositive hydrogen bonds to electronegative atoms (O, N, or F)
Gives water it’s angular shape
The three forces have different strengths in their bonds
London forces are weakest and exist between all molecules – the idea is that there will always be some form of “polarity” or dispersion of charges within atoms and molecules
This small “polarity” allows for atoms and molecules to attract to one another but it is very weak and can be broken and reformed quickly – as temperature changes, so does the strength of this force (liquid to gas)
Dipole-dipole forces is the bonds between polar molecules
The polarity causes the attraction between molecules
Hydrogen bonds between water molecules gives water it’s stickiness
Acids and Bases
Strong acids and bases dissociate completely in water
Weak acids and bases dissociate only partially in water
Acid + Base 🡪 Water + Salt (Neutralization reaction)
The pH scale measures the acidity of a solution
Biological Molecules
Biological molecules range from very small to very large
Monomers are individual subunits that can be joined together to create chains called Polymers
Biological molecules range in size
Monomers are small subunits (such as one molecule of glucose)
Polymers are larger units composed of monomers coming together (such as lactose)
Biochemical Reactions
Polymers can be broken down into monomers (releases energy)
the bonds store energy, this breaking reaction releases energy → exothermic reaction
usually energy is released as heat
breaking
Monomers can form polymers (stores energy)
can use the monomers to make bonds which store energy.
we need to put energy into this reaction/bonds to complete this reaction
building
Types of Biochemical reactions
Four Types:
Hydrolysis Reaction: hydro is water, lysis is breaking something down→ to break something down with water
Dehydration Synthesis Reaction
Neutralization Reaction
Redox Reaction
In biochemistry, we can either make larger molecules (by bringing smaller molecules together) or break larger molecules (into smaller molecules)
There are specific types of reactions that occur to make or break specific types of molecules
The first two reactions will deal specifically with the addition and removal of water
Hydrolysis reactions
Catabolic reaction (breaking down)
The word hydrolysis means “water” and “to split”
We are breaking big molecules to small molecules (digestion)
Water is used to break molecules apart
glow stick breaks apart to glow → creating energy
Dehydration Synthesis (condensation) Reactions
Anabolic reaction (building up)
taking out water
A synthesis reaction produces a larger molecule (polymer) from smaller parts
We are making larger molecules from small molecules
Water is produced during the reaction
Neutralization Reactions
Reaction between an acid and a base
Buffers
Buffers:
chemicals that minimize pH changes
important in homeostasis
water is a buffer, donates and accepts hydrogen ions
take H+ or OH- to maintain pH in the blood and for enzymes to function
see it a lot in digestion (e.g. chyme entering the duodenum; pancreas secretes sodium bicarbonate to neutralize chyme
