Plant - Water Relations OLD NCERT CLASS XII textbook chapter 1 main points

Here're the main, unheard points from Plant - Water Relations chapter of  OLD NCERT CLASS XII BIology textbook chapter 1

protoplast=plasma membrane+protoplasm
plasmalemma = plasma membrane
plasmodesmata connects protoplasm of adjacent cells

Water potential
1 Megapascal, Mpa = 10 bars
water potential = solute potential +pressure potential + gravity potential
solute potential = osmotic potential
pressure potential = hydrostatic pressure
turgor pressure = positive hydrostatic pressure. can increase only till the cell becomes turgid after which the wall pressure prohibits further increase in size
gravity potential is negligible for height less than 5 m

absorption and movement of water
symplastic pathway is transmembrane pathway (water may also cross tonoplast)
osmotic potential is the negative of osmotic pressure (required to balance it)
matric potential (water potential of the matrix) = imbibition pressure

Water translocation theories
root pressure

capillarity = rise in water in tubes of small diameter kept in a vessel containing water
cohesion theory given by henry dixon in 1914
walls of xylem vessels are made of ligno-cellulose (high affinity for water)

transpiration
factors affecting: humidity, temperature (evaporation doubles with rise of 10 degree rise. But high temperature closes down stomata), wind speed, efficiency of water uptake by roots, leaf area, leaf structure.
(thick cuticle, sunken stomata in dry habitat plants to reduce)

Stomata
size of pore 3-12 micrometre wide, 10-14 micrometre long. 1000 to 60 000 per sq. cm.
abaxial (b for base, lower) stomata is more in dictots than adaxial (d for dome, upper)
the major solute taken in by guard cells is potassium
this uptake is electrically balanced by uptake of chloride and malate (obtained from hydrolysis of starch)
even moonlight is sufficient to keep stomata open in some plants
in CAM plants, stomata open during dark, close during day (pineapple, agave)
stomata tend to open more with increase in temperature (not very high temperature)
water stress, (water deficit or moisture deficit) induces stomatal closure.

http://books.google.co.in/books?id=kQca-rKGXV0C
http://www.google.co.in/search?q=%22This+happens+to+conserve+moisture+by+plants+by+cutting+down+the%22&hl=en&biw=1267&bih=930&prmd=ivnsb&filter=0

you can find everything in these books from there... why shud i waste time typing..

Thermodynamics

www.introphysics.info/IntroToEqThermo/Thermo.pdf
read that before reading anything else on earth.

Physics and Chemistry have opposite conventions over choosing the sign of work done. That is a FACT! (It's not that you are confused)
In physics, work done by the system is taken as positive.
In chemistry, work done on the system is taken as positive.

The only way to escape this stupid convention tricks, is to really know what's happening.

U, internal energy is the sum of potential, kinetic energies, etc of molecules in a gas. (And here's the killer tip. For ideal gases, we neglect the potential energy, etc. So internal energy is directly the kinetic energy. And temperature, as we'll learn in kinetic theory, is a function of kinetic energy. So, internal energy is directly measured by temperature for IDEAL gases)

Q is heat applied. Thankfully it's taken positive when heat is applied to the system in both physics and chemistry.
(And when heat is applied to the system, we are supplying energy to the system, that is to say the internal energy rises)

W is work done. (Let's forget if it's by the system or on the system)
When we try to contract the gas, we hit the molecules and inadvertently add to their kinetic energy. So, internal energy increases when the gas is contracting.
When the gas is expanding, the molecules give up a part of their kinetic energy to push the wall around. So, internal energy decreases on expansion.
When we are pushing a piston as in the textbook, W is PΔV only. You don't need to add VΔP. We are not differentiating. We are only finding FΔs
F=PA (actually the P is the external pressure. Can't type subscripts, that's why)
AΔs=V
So, W = P A Δs = P ΔV


ΔU=ΔQ+ΔW as per chemistry textbook.
ΔU=ΔQ-ΔW as per physics textbook.
Both read the same, as the sign of ΔW would be opposite in both.

Now, let's see what happens during thermodynamic processes.
Isothermal expansion or compression.
When compressed, as I told earlier, the internal energy should increase.
But since it's isothermal the internal energy can't increase. (ΔU=0)
So, what do we do? Give out that energy as heat!
And during expansion that much heat energy is absorbed as much as is expended in expanding.
Let's try to quantify this heat released (or the work done) in terms of P, V, etc.
Since it's isothermal, T is a constant. And we know that PV=nRT
Now when we are compressing the gas, we are decreasing the volume from V1 to V2. That SHOULD be accompanied by a proportional increase in pressure from that formula.
Now we've found W=PΔV. Can we just plug in P as the pressure right now, and ΔV as V2-V1 ??? (The P would be external atmospheric pressure)
Well, that's what happens when a gas bomb explodes. All it takes is an instant, and it'd expand to its final size.

Extra reading
http://galileo.phys.virginia.edu/classes/152.mf1i.spring02/CarnotEngine.htm

Amines

There's a villain hiding in nomenclature. What is benzenamine? You probably imagined a phenyl group, a CH2 group and then NH2. No. What you imagined is phenylmethanamine. More correctly 1-phenylmethanamine. (Here, phenyl group becomes substituent as the side chain becomes the main chain) Benzenamine is nothing but aniline.

We'll begin with the basic character of amines, and I gotta say the table 13.3 in page 389 is utterly useless. It doesn't write things in the order of basic nature.
Here's the real thing.
From Most basic in aqueous phase
N-Ethylethanamine
N,N-Diethylethanamine
N-Methylmethanamine
Ethanamine
Methanamine
N,N-Dimethylmethanamine
Phenylmethanamine
Ammonia
N,N-Dimethylaniline
N-Methylaniline
Aniline (or Benzenamine)
To Least basic

Let's try to make sense.
Basic character, for amines, is due to that lone pair on N:
The more the electron density on the N, the more basic it must be, then.
-CH3 group is electron donating by +I
-C6H5 is electron withdrawing
So that explains why aromatic amines are less basic than ammonia, and aliphatic ones more basic.

But in water there's solvation effects to be taken care of. There's hydrogen bonding. The more the hydrogen bonding, the more stabilization of the positive charge on N (due to the loss of its electron pair). So when there's lesser substitution, there's more stability. (But ammonia can't still overtake substituted aliphatic amines. it's just the order among the substituted amines that we're talking about)
So, the disubstituted ones end up stronger, because they've two hydrogen bonds, and 2 -alkyl groups.
And now that order in page 391 makes sense. (It can be observed that roughly, inductive effect is stronger than solvation effect. That's why (C2H5)3-N is stronger than (C2H5)NH2. And in the second line, methyl groups don't have so much +I effect. So they follow the order of solvation effect.

Why aromatic ring takes away electron is pretty well known. There's resonance, there's this sp2 carbon. There're a lot of things.

Periplaneta americana

Arthropoda --> Insecta

green

red

Ok. They say bright yellow too has been spotted in tropics (what's not in tropics?) (FYI: tropics is between tropic of cancer and tropic of capricorn... amazon, etc. you know?)

1/4 inch to 3 inch. 3 inch is half that 15 cm scale you all take to school in the box.

It's got that extension of upper body wall which makes it look like the pandy lorry.

They eat anything and everything. That's what makes them pests, able to survive anywhere (some people don't go out of their home state because they don't eat all food). And of course they're omnivores. Don't mind whether it's veg or non-veg that they eat.
And not just that. They transport E.coli, staphylococcus, salmonella, etc. causing diseases.

Look :
Like the upper body wall that extends over head, the wings extend on the behind, beyond the abdomen.
Like all insects (like ant), there're three main sections. Head, thorax, abdomen.

sclerites (sclero-hard. (remember sclerenchyma?) plates of exoskeleton)
dorsal tergites and ventral sternites (sternum(breastbone) is ventral).
these are joined together by arthrodial membrane (arthro - joint, rheumatoid arthritis at knee joint) (or articular membrane... articulation is also joint)

Cockroach is humble, has its head bowed at right angles to the body.
Antennae + eyes = martial sense of surrounding.
labrum and labia both mean lip. But labia stands for 2 lips (labia majora and labia minora are 2 pairs of folds that're perfect for lips). labium the lower lips is made of 2 sides, 2 appendages, etc. see the figure. Those things couldn't be fitted on to the upper lip, because then it'd obstruct the mouth. labrum the upper lip is single.
Now here's the not so easy part. Mandible and maxilla both mean jaw. Mandible is that which allows chewing, grinding, etc. (In human beings the mandible is the lower jaw. And maxilla the upper jaw.) But Periplaneta has got no hands to take food near the mouth. So, one jaw (preferably the lower jaw) took appendages that take food to mouth. The other (upper) has grinding, and incising regions. So, upper is mandible, lower is maxilla. ( these are paired for Periplaneta, because it's gotta be around the labrum and labium.)
hypopharynx is tongue. it's upside down. pharynx is above. hypopharynx, under pharynx.
Head ---- neck-pro ---- meso -----meta
pro means earlier, anterior, etc (prokaryote)
meso means middle (mesoderm, mesosphere)
meta means beyond, later, after development (metamorphosis)
Each of these got a pair of legs each. (Like ants. Head and abdomen would look eerie had they had legs)
The pro thorax's already gotta bear the neck. So it doesn't have wing.
Forewings, are at mesothorax.
(LOL. As I type that I spot an old, grown cockroach on the floor. Let us call him (oh, wait is it he? lemme see...Oh, it's got style. It's a male. Oops. seems like it didn't like the photo flash. Crept out of my hand. Let's let it go its own way. Lesson learned. No flash photography with nocturnal vision animals. (extreme sensitivity))

Huge Mnemonics Collection for AIPMT, BIOLOGY, AIIMS

http://www.valuemd.com/genetics.php
DNA: Z vs. B form: which is inactive
ZZZZ is sleeping (inactive). B form is therefore active DNA.

DNA bond strength (nucleotides)
"Crazy Glue":
Strongest bonds are between Cytosine and Guanine, strong like Crazy Glue (3 H-bonds), whereas the A=T only have 2 H-bonds. · This is relevant to DNA replication, as the weaker A=T will be the site where RNA primer makes the initial break.

Nucleotides: purines vs. pyrimidines
Guardian Angels are Pure, with two Wings: G and A are Purines, with two Rings.

http://www.technion.ac.il/medicine/Students/Mnemonics.htm
Pyrimidines are CUT from purines.
Pyrimidines are Cytosine, Uracil, Thiamine and are one ring structures.
Purines are double ring structures.
Amino Acids:The ten essential amino acids:
"These Ten Valuable Amino Acids Have Long Preserved Life In
Man."
(Threonine, Tryptophan, Valine, Arginine, Histidine, Lysine,
Phenylalanine, Leucine, Isoleucine, Methionine)

WBC Count:
"Never Let Momma Eat Beans(60, 30, 6, 3, 1)
Neutrophils 60%
Lymphocytes 30%
Monocytes 6%
Eosinophils 3%
Basophils 1%

The 5 sphincters found in the Alimentary Canal are APE OIL:
Anal, Pyloric, Lower Esophogeal, Oddi, and Ileocecum.

http://www.valuemd.com/biochemistry.php
Sickle cell disease pathophysiology
SICKle cell disease is due to a Substitution of the SICKsth amino acid of the B chain.

Sickle cell anemia: mutation
"HbS isn't Very Good":
At Sixth position of HB beta chain, Valine is present instead of Glutamic acid.

Glycolysis steps
"Goodness Gracious, Father Franklin Did Go By Picking Pumpkins (to) Prepare Pies":
Glucose
Glucose-6-P
Fructose-6-P
Fructose-1,6-diP
Dihydroxyacetone-P
Glyceraldehyde-P
1,3-Biphosphoglycerate
3-Phosphoglycerate
2-Phosphoglycerate (to)
Phosphoenolpyruvate [PEP] Pyruvate · 'Did', 'By' and 'Pies' tell you the first part of those three: di-, bi-, and py-.
· 'PrEPare' tells location of PEP in the process.

B vitamin names
"The Rhythm Nearly Proved Contagious":
· In increasing order: Thiamine (B1) Riboflavin (B2) Niacin (B3) Pyridoxine (B6) Cobalamin (B12)

Citric acid cycle compounds
"Oh! Can I Keep Some Succinate For Myself?":
Oxaloacetate Citrate Isocitrate Ketoglutarate Succinyl coA Succinate Fumarate Malate

Citric acid cycle compounds
"Oh Citric Acid Is Of (course) A SiLly STupid Funny Molecule":
Oxaloacetate Citrate Aconitate Isocitrate Oxalosuccinate Alpha-ketoglutarate SuccinyL-CoA SuccinaTe Fumarate Malate
· SilLy and sTupid used to differentiate succinyL and succinaTe

Citric acid cycle compounds
"Can I Ask Sharon Stone For My Orgasm?":
Citrate Isocitrate Alpha-Ketoglutarate Succinyl CoA Succinate Fumerate Maleate Oxaloacetate

Pyruvate: products of complete oxidation
"4 Naked Fun 3 Coeds + 1 Guy":
· Complete oxidation of pyruvate yields:
4 NADH FADH2 3 CO2 1 GTP

Enzymes: classification
"Over The HILL":
Oxidoreductases
Transferases
Hydrolases
Isomerases
Ligases
Lyases
· Enzymes get reaction over the hill.

http://www.valuemd.com/genetics.php
Blots: function of Southern vs. Northern vs. Western
SN0W DR0P:
· Match up the 1st word letter with 2nd word letter:
Southern=DNA
Northern=RNA
Western=Protein
· The 0's in snow drop are zeros, since there is no Eastern blot.

Hardy-Weinberg equilibrium: causes for deviations from it
Maggie May Does Not Smoke:
Mutations Migration Drift Non-random mating Selection

Why are autosomes called so?

The 22 pairs of chromosomes of our cells, that aren't sex chromosomes, are called autosomes.. because 'auto-' means 'self' or 'same'... These pairs always contain the same chromosomes unlike the sex chromosomes which may vary as X & Y.

Parallel Plate Capacitors in Series Combination

If you ever wondered how parallel plate capacitors in series combination works, here is the real explanation (with the electron flow explained)
First let us start with a single capacitor in circuit.
When a capacitor is connected to a voltage source, the emf of the source drives electrons from its negative to one of the plates of the capacitor (say A) and the positive electrode of the source pulls equal number of electrons from the other plate (B)

Now if A is charged -Q, B will be +Q. (Wait to hear why it's both Q and not Q and q)

This difference in charges produces a potential difference between the plates. which is opposite in direction to the potential of the source. (because A is negative, and the terminal connected to A is also negative)
Thus the potential differences cancel out and since there's no more force, no more flow of charge.
The capacitor is said to be charged Q. (Not 2 Q because only Q amount of charge is in there that can be used)

(Now we can say why they're both Q. Because nature isn't so partial about positive or negative charge. If it gives electrons to one side, it will also love to take electron from the other side equally well)
(But what if we introduce a resistance R in one side - that is left for you)

Now when two capacitors are connected in series:
From left to right A,B,C,D are the parallel plates. A&B form the first capacitor, C&D the next. Let A be connected to negative terminal itself. (We will see that the plate B, the plate C and the wire that connects these two plates form an isolated system of net charge = 0)
Now electrons flow to A (charging it to -Q)
Due to induction there'll be +Q on B, -Q on C and +Q on D

Why +Q itself on B (I don't know)
What if the area of plate B is only half the area of A (I don't know)

But this is what happens.