• dilute salt solution has a higher water potential than the cell sap roots




• cell sap roots has higher salt concentration( high salt concentration= low water potential), lower water potential than the dilute salt solution.




• when water enters cell sap. the cell that has water will have higher water potential than its neighbouring cell. osomosis will be passed down till it reach the xylem.








• But why high concentration= low water potential?




• because for a lower concentration substance, every molecule is smaller than those of a higher concentration,




• take bandung and water for example, .(imagine) if both were to flow water will flow faster as it have smaller molecules.
  


• osomosis is only for water
  

active transport:

MINERAL SALTS enter cells through active transport ( when the concentration in the cell sap is high)

definition: active transport is the process in which energy( taken from respiration) is used to move substances from a region of low concentration to a region of high concentration.

thus, the low salt concentration from the soil solution is pulled into the high salt concentration of cell sap root haialthough the cell sap root hair have a higher salt concentration, and diffusion can take place out of the cell. but because of the permeable membrane of the root cell, diffusion is unable to take place as the membrane controls the substance that goes out of the cell.

XYLEM AND PHLOEM TUBE:

for the cross section of the xylem and phloem tube, xylem tube is the inner part and phloem is the outer.

xylem:long hollow tube

-strengthened with lignin

-made up of dead cells

-a tube that brings water and mineral salts dissovled in it from roots to all parts of plant. It also provides support to the plant

-transpirtational pull- is a pulling force that brings the substance up the xylem tube

phloem:

transport the glucose produced in the form of sucrose to all parts of the plant

water enters the plant through roots >>water and carbohoydrates goes all parts of the plant>>water being tranported to leave by xylem tube>>water exits plants through stomata in leaves in a gaseos state( water vapour)

root hair cell

- where water and mineral salts enter

-special root cells that are long and thin at tip of the roots

increases surface area of roots

-can absorb water+ mineral slats.

why does root have root hair cells?
answer:to increase the surface area to volume ratio . water and mineral salts will take less time to enter the plant.

transpirational pull:

transpiration: loss of water vapour from stomata

pulling the column of water in the xylem up to the leaves.

-water evaporates from surface of plant cells ( high concentration of h20 vapour in leaves)

-high H20 vapour content in leaves diffuses out to low H20 content

------------------------------------------------------------------------------------------------hi dancers
as i have promised. the notes. for chem but its chapter 1 only. i try post up more when im done with it. the time now is 1246am.!!!!! late late late! have fun!=)

haha, halfway through , if got any error , spelling , typo or wrong info. please dont blame me , caused im not a licensed tuition teacher. LOL



CHEMISTRY: particulate model of matter.



matter- anything that occupies space, has mass ,can exist as the SLG

PARTICLES
- small/discrete/ invisible and cannot be seen with microscope
-spaces between aprticles
- diff space of particles in between SLG
-particles are at constant and random motion
SLG moves in differnent speed.
this is the KINETIC THEORY OF MATTER

kinetice particle theory= all matter is made up of small discrete particles which are in continous and random motion.




solid, liquid gas , have different properties.






click for a larger view. this is about solid , liquid and gas.

some questions

1) It is easier to compress a gas than a liquid or solid
ANS: infer that spaces between particles for gas , is larger than solid and liquid particles.

2) Diffusion occurs in liquid but much slower than diffusion in gas.
ANS: Gas particles are further a part, spread more than liquid particles.

DIFFUSION:

movement of the substance from a region of high concentration to a region of low concentration.

In diffusion, the particles will mingle and move through other particles of another ( natural mixing)
DIffusion will stop when it reach a state of equilibrium. diffusion is also constant unless got barrier

Particulate model of matter: EXPANDSION AND CONTRACTION.

when a substance is heated, the substance or object will expand
when it is cooled, the substance/object will contract.

but the particles in the object/substnace do not become smaller or bigger( or dont contract or expand ).
the spaces in between each particle is the thing that expands and contracts, causing the change of size in the object /substance.

when heated , the particles will move faster and away from each other,
when cooled, the particles will vibrate lesser and move closer.
(p.s , take note that substance is substance , particles are particles)

process of MELTING

from 0C , when water is in the form of solid. WITH HEATING
the ice warms and the temperature rises, causing the ice to melt. the particles in the solid will start to vibrate as it gains heat .( kinetic energy increased). the temperature will remain constant first because the heat energy absorb by particles is used to overcome forces of attraction that is holding the particles together. At a particular temperature, the particles will vibrate so violent that it overcomes and breaks off the force of attraction, and now the particles are break away from each other. this is when the solid particles have changed to liquid particles.
the temperature will start to warm up as boiling continues. temperature remain constant at a particular temp as the heat energy absorb by the particles is used to break down the forces of attractions holding the particles together.
the liquid gains heat energy , vibrating faster and faster, and when it violently vibrates at a certain temperature,the partcles will move further from each other adn the forces of attraction is broken. thus the liquid turns in to gas.

CONDENSATION AND FREEZING
when gased is cooled, it changes to liquid = condesnation
in a graph, there will be a plateau, it shows that as the gas condense, the temp will remain constant , as energy liberated as the particles attract one another to form a solid.

comparing properties of matter with properties of particles:
-matter may be coloured, but the particles are not coloured
-substance can feel hot or cold, but particles cannot. particles will jsut increase or decrease in kinetic energy.

i just go abit into atoms, since im lazy to draw.

atoms- smallest particles of an element which retains the chemical properties of that element.
element- is a pure substance that cannot be broken down into 2 or more simpler substance by physical or chemical means

atoms is chemically stable if its outer most shell is completely filled when contain 8 electrons (octet rule)

ions( got to do with electrons only)
- loss or gains of electrons int eh outer most sshell of atoms results in teh formation of ions. thus i will not be nuetral anymore.
loss of electrons will result in cation(positive ion)
gain of electrons will result in anion( negative ion)


done. phew.

lukhei

oh yeah and dont forget, this one.

the bulb here wont light up. it is a short circuit. the bulb has resistance. but this parralel circuit has one path that do not have bulb which measn an negligible amt of resistance. Electric current will go to the path with lesser resistance. thus the bulb doesnt lights up as current doesnt flows there. and the wire will turn hot after awhile.

chapter 10

electrical appliance POWER= the amount of electrical energy it converts in a second.

SI unit= W( watts)formulae for power is: P= VxI( power= voltage x current)

calculating quantity of energy consumed is =power x time(KiloW attsx hours)( kWh)must be change to kilo watts before calcutaling the quantity of energy consumed.

in a 3 pin plug, there is 3 main wires called live wire( brown coloured), neutral wire( blue coloured) and earth wire( yellow and green)

the earth socket is planted to the ground and electricity does not flow in earth wire. it flow in live and neutral wire. the metal part of the appliance is connected to the earth pin.

this is to make sure that , if ever the live wire accidentally touches the appliance, humans wont get electric shock when they come into contact with the appliance or they will be shocked. , this earth wire will enable most of the current to flow through the wire to the ground instead of through the body. and because the earth wire has lesser resistance than the human body , the electricity will flow to the earth wire .

FUSES>

fuse rating - the maximum current that can flowing through a fuse.

a fuse will melt and break when the current passing through it is greater than its rating. the fuse is blown

the wire in the fuse is made of tin alloy which have low melting point nad can melt easily.

they prevent wires or appliacnes from getting too hot to start a fire.

lukhei.

• okay im seriously thinking that the dance blog is totally spam with notes. haha sorry ya, but good luck for ur eoys. and heres digestion for biology notes. take your time to read coz bio exam is in the next month.

• found in small amount in all animals.





• is the product of photosynthesis found in plants

Fructose

• common in plants and rare in animlas( grapes, melon.)

Galactose

• presnet in the milk sugare of all animals from milk
  

Maltose

• found in barley , all sprouting grains
  

Sucrose

• sugarcane , stems , sweet furit , certain storage roots like carrot
  

lactose

• milk of all mammal
  

Starch

make and stored in plants root in animals

Glycogen

• made and stored in fungi adn animals but not plants

cellulose- main constituents of cell walls of plants cells , can only be digested by a few organisms. forms fibre of diets of mamals, as cant be digested

-helps to remove faeces;

PROTEINS:

each protein molecule is made up of many amino acids bonded together

-each protein molecule can consist of between 2 to several thoursnads.

there are 20 naturally occuring amino acids.

amino acid+amino acid= dipeptide

many amino acids= polypeptitide/ peptones

peptones join together as proteins.

egs of proteins are

SOYA BEAN!!

VEGETABLE(YUM@!!!)

NUTS, GRAINS ETC.

animals: seafood, meat,(chicken and lean beef!!)

fats!

sources- butter cheese, palm oil, fatty meat, olives, nut, peas,beans, seeds of castor oil, salmon and herring.

white meat & most fishes have less fasts ( except salmon and herring)

fat iis NOT An essential dietary nutrient. in humans.

uses of fats

: source of store of energy

provide highest amount of energy

-good insulating material under skin

-reduce loss of body heat esp. for mammals living in the water which cannot reduce heat loss with hair.( blubber)

CONSTITUENTS.

FATS: consist of carbon , hydrogen , oxygen. it is different from carbhohydrates as the ratio of the hydrogen is much than that of the oxygen.

eg C6 H121 O5.

CARBOHYDRATES: consits of carbon , hydrogen , oxygen. the ratio of hydrogen is twice of the oxygen.

eg.C6 H44 O22

PROTEINS: consist of carbon , hydrogen , oxygen adn NITROGEN.

eg C6 H22 O11 N8

why do we need food?

- for energy to work out muscles and all other organs.

- grow new cells and tissues

-repair damaged tissues repair damaged tissues

-maintain body functions such as breathing and keeping the heart beating.