revision: Biology - Topic 2

i'm working through this slowly so if there's a topic you want me to cover now you can comment! also do so if there are any questions and i will explain anything to you here :) thank you!! i hope this is useful!!

UPDATE: If you guys want definition of keywords, don't forget you can use 'Ctrl + F' and type in your word :)

If you can't see the pictures or diagrams, if you click on them, they'll get bigger!!!!!!!! :D

Although the subjects listed on the side are the ones I take, soon you guys will get more subjects like Economics and stuff since my friend will be helping out :) Thanks to her!

I'll still write most of my revision though, so no worries xD You guys motivate me to revise actually ^^""" 

KEYWORDS-

Aerobic respiration - the process of releasing and obtaining energy requiring oxygen and glucose.

oxygen + glucose -> carbon dioxide + water and energy

Anaerobic respiration - the process of releasing energy without oxygen producing lactic acid.

glucose -> lactic acid
(*IT DOES NOT GIVE US CARBON DIOXIDE AS THERE IS NO OXYGEN.*)

Fermentation - the form of anaerobic respiration and process of releasing energy in plants and yeast. (Unicellular organisms)

glucose -> ethanol + carbon dioxide
(ethanol is an alcohol therefore this process is also used to create alcoholic beverages such as beer or useful substances like biofuels.)

Lactic acid - the substance that glucose is broken down into during the process of anaerobic respiration to release energy in our muscle cells. Build up of this causes fatigue and cramps, oxygen must be replenished to break this substance down.

Oxygen debt - the build up of an oxygen debt due to respiring anaerobically is the amount of oxygen needed to be replenish to oxidize lactic acid build up in our body (muscle cells) and break it down.

2F- RESPIRATION

2.33 - understand that the process of respiration releases energy in living organisms.

-Basically, what was said above about aerobic, anaerobic respiration and fermentation haha.
-Respiration takes place in cells. DUH.
-Oxygen oxidizes food and carbon dioxide and water are released as waste products.
-Respiration releases energy in the form of ATP molecules. (ATP molecules are just energy...but the "pro" way of writing it :D)

2.34 - describe the differences between aerobic and anaerobic respiration.

-The difference is that aerobic respiration requires both glucose and oxygen in which we breath in, this results in the oxygen breaking down the glucose leaving us with carbon dioxide which we breath out and water (sweat and all that xD) and...of course...energy.

-Anaerobic respiration however, is when our body uses only glucose to produce energy, without oxygen. 

-This happens when we do not take in enough oxygen (like when you do sports...basketball and all that and you panting and sweating ya know :D)  

-but....we still need energy...so our body just makes it with glucose ONLY. 

-The :( thing is...we get lactic acid as a by product and that's not good for you because you build up an oxygen debt...lactic acid will give you PAINFUL cramps and you feel tired (fatigue) so...you gotta breathe in oxygen to replenish for the oxygen debt you build up from respiring anaerobically AND...oxygen breaks down LACTIC ACID :) And that's why we need it to live :D :D :D

2.35- write the word equation and balanced chemical symbol equation for aerobic respiration in living organisms.

-ALREADY UP THERE...but...

Aerobic respiration - the process of releasing and obtaining energy requiring oxygen and glucose.

oxygen + glucose -> carbon dioxide + water and energy
It takes place in the mitochondria

The symbol equation is----

(*Anyone watch 'The Mentalist'? Cuz the way I remember glucose is because of that Asian guy. Agent Cho is his name and C6 H12 O6 is GLUCOSE :D )

2.36- write the word equation for anaerobic respiration in plants and in animals.

-Already up there but....

This takes place in the cytoplasm...

ANAEROBIC RESPIRATION in animal cells (occurs in muscle cells -.- cramps -.-) - 

glucose -> lactic acid (and energy)

ANAEROBIC RESPIRATION in plant cells (yeast and people getting drunk on beer and stuff xD)-

glucose -> ethanol + carbon dioxide (and energy)

ethanol is an alcohol and to test for the carbon dioxide = lime water turns milky :)

(REMEMBER = this is what happens in bread...the smell? it's yeast :) but then...why don't we get drunk on bread? haha that'd be cool but...the ethanol evaporates due to baking the bread...and the carbon dioxide are the holes that bread has? Get it? :D :D :D LOL. If we could get drunk on bread...)

2.37 - describe the experiments to investigate the evolution of carbon dioxide and heat from respiring.

UPDATE - THIS ONE IS NOT ON THE TEST...
Apparently an email was sent stating this....
(9/1/2013 10pm)

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KEYWORDS-
Monomer- small single soluble molecules that can enter your blood stream.
Polymer- chained structures of molecules made of monomers, these cannot enter you blood stream and must be broken down by their respective enzymes.
Amino acids- the monomers that make up a protein polymers, there are 26 different types.

Monosaccharide- the simplest form of carbohydrates which cannot be broken down
Disaccharide- two monosaccharides
Polysaccharide- more than two monosaccharides are joined together.
Lipid- a type of molecule made of carbon, hydrogen and oxygen. Examples are fats and oils.
Cellulose- The polymer carbohydrate that makes up the plant cell wall and cannot be digested by humans.
Starch- A polymer which can be broken down into glucose and is a main source of carbohydrates. Plants store starches inside
Active site- The site where the reaction of breaking down a substrate takes place.
Denature-When an enzyme is destroyed or changes shape and can no longer break down substrates as it's original characteristics are lost.
Optimum- The perfect condition.
Substrate-The molecules that are broken down by enzymes - starch, protein, lipids.

2.5 - identify the chemical elements present in carbohydrates, protein and lipids (fats and oils)

Okay...

Carbohydrates should be easy no?
CARB-O-HYDRATE
-.-
Carbon, hydrogen and oxygen 
Remember glucose? Remember Agent Cho? Yes him. HE IS ASIAN. He is also...CARBOHYDRATES :D

As monomers (small soluble molecules that can go into your blood stream), carbohydrates exist as glucose.

Glucose is stored in plants as starch.

Proteins are the same...
Carbon, hydrogen, oxygen but it's got more! It's got nitrogen too :)

Altogether, there are 26 different amino acids that are monomers which form the polymer protein, the order of these amino acids in the chain makes different protein polymers.

Lipids - (fats and oils)
Oh look, Agent Cho is also fat. And oily :) (No offense, Agent Cho, you're daebak :D He's Korean btw :D)
Yes, that means lipids contain Carbon, Hydrogen and Oxygen too.

There are only two kinds of lipid monomers, these are glycerol and fatty acids.

*If you haven't realized by now, you can ignore the stuff I write in brackets sometimes haha.

2.6 - describe the structure of carbohydrates, proteins and lipids as large molecules made up from smaller basic units. starch and glycogen from simple sugars (glucose), protein from amino acids, lipids from fatty acids and glycerol.
Here's a table to clearly show :)

I think syllabus 2.29 is similar to this? (Correct me if I'm wrong :D)

2.7 - describe the tests for glucose and starch

benedict's solution will change from clear blue to orange/yellow if glucose is present when placed in a bath at 60 degrees celcius.
iodine will turn blue/black from orange/brown in presence of starch.
You just gotta remember this...I'm sorry...

2.8 - understand the role of enzymes as biological catalysts in metabolic reactions

-biological catalysts are substances that are able to speed the rate of reaction without being affected themselves.

 -these metabolic reactions take place in cells.

-Enzymes break down polymers such as starch, protein and lipids into smaller particles known as monomers.

 -The polymer substrate and the active site of an enzyme fit each other like a lock and key. They are complimentary.

 -Monomers are small soluble particles that can enter our blood stream and be of use.

Starch is broken down by the enzyme amylase found mainly in our saliva and small intestine is broken into maltose which is then broken down by maltase into glucose.

Protein is broken down by the enzyme protease found in our stomach (slightly acidic to kill of bacteria) and small intestine is broken down into amino acids.

Lipids are broken down by the enzyme lipase and are broken down into glycerol and fatty acids.

2.9 - understand how the functioning of enzymes can be affected by changes in temperature, including changes in active site caused by changes in pH.
-increase in temperature = increase kinetic energy particles.
-increase in kinetic energy = increase in number of collisions.
-These result in more reactions.

2.10 - understand how the functioning of enzymes can be effected by changes in the active site caused by changes in pH.

-Rate of reaction decreases as the conditions become more acidic or alkaline (however this depends on the optimum pH of each enzyme)

-Acidic and alkaline conditions above an enzyme's optimum pH also changes the shape of the enzyme active site.

-Not all enzymes have optimum pH of 7, different enzymes have different optimum pH.

2.11 - describe experiments to investigate how enzyme activity can be affected by changes in temperature.

(I have no idea... O_O I'm really bad at these experiment questions ahaha...)

HELP? D:

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Human Nutrition

2.23 - understand that a balanced diet should include appropriate proportions of carbohydrates, protein, lipid, vitamins, minerals, water and dietary fibres.

DIET = LIFESTYLE

DIET = carbohydrates, proteins, lipids, vitamins (A, B, C), minerals (Ca, Fe), water and dietary fibres.

LIFESTYLE = age - gender - activity - pregnancy

PROTEIN, CARBOHYDRATES, LIPIDS, VITAMINS, MINERALS must balance with the demands of your lifestyle!!!!!!

(That means you can't skip meals :) If you do, I will find you...and shove food in your mouth -.-" And if you don't eat EVERYTHING you might be constipated...then you'll have a face like...)

2.24 - identify sources and describe functions of carbohydrate, protein, lipid (fats and oils), vitamins A, C and D, and the mineral ions calcium and iron, water and dietary fibre as components of the diet.

Carbohydrates = 
Starch from rice, potatoes, etc.
Provides us with energy through respiration.
(I <3 Rice :D Oh so ASIAN :3 You know, there's a K-Pop group called B.A.P? Apparently that means rice in Korean haha xD)

Glucose can be used straight away, the starch has to be broken down into glucose. When glucose is released, energy is produced.

Protein = 
Animal protein, fish, plants (beans and seeds.)
Growth of muscles, repair (to make new cells), we cannot store protein.
(EWWW. I hate beans D: No...wait...I hate nuts D:)


Lipids =
Animal fat, fish oils, palm oil, sunflower oil, etc.
Stored energy and insulation and protection (?)

Fibre =
avoids constipation, adds bulk to food so it moves through the small intestines,  it does not get digested.
-Plant cell wall. - Carbohydrate cellulose.
-Plants in our diet.
-Maintain peristalsis.

Vitamins =
A = to produce light sensitive pigments in our eye so we can see in low light conditions.
-Fish liver oils, liver.
-Night blindness

C = forms connective tissues, help cells stick to each other.
-Citrus fruits
-Scurvy -> symptoms are bleeding gums.

D = absorb calcium from our diet -
-spend time in sunshine, fish, fat, egg.
-rickets -> bending of bones.

Minerals = 
Iron = to make haemoglobin in red blood cells
-Liver, spinach
-Anemia -> unable to produce haemoglobin -> tiredness, pale.

Calcium = to increase bone strength
-Dairy products, milk.
-Rickets

Water =  to maintain solutions.
-Chemistry of life.
-Drink water or in other foods.
-Dehydration.

2.25 - understand that energy requirements vary with activity levels, age and pregnancy.

Basically, if you're athletic, you need more energy so you eat more and don't get as fat :P
And if you're pregnant, which I'm sure none of you are...are you? then you're gonna need energy for that growing little bald creature :D AKA a baby. or a fetus. -.-
And...if you're a teenage girl...and know the pains of being a girl...you're gonna need more iron...cuz you know...we lose more...BOYS. I'd just go with it when I say "Girls need more iron."

And of course, bigger older people need more energy than little babies :D
THAT IS IT! EASY?
GOOD.

2.26 - describe the structures of the human alimentary canal and describe the unctions of the mouth, oesophagus, stomach, small intestine, large intestine and pancreas
We ingest food from our  mouth where chewing takes place. Saliva (including amylase which breaks down starch into maltose) and mucus is added for digestion and lubrication.

Our partially digested food tavels through our oesophagus by a process called peristalsis, (I spelled it wrong in the diagram -..-) anyways...it's muscle movement :) No digestion takes place here.

Our food then goes through our stomach which contains stomach acid that will kill all bacterias in our food. Also, protease which breaks down protein is also present.

Our liver there produces bile and our gall bladder stores it. Bile is used to neutralize the digested food from our stomach (acidic conditions) as well as emulsifies fats splitting them into smaller particles but not breaking them.

The food then gets to our pancreas, neutralized where complete digestion takes place.
Protease, lipase and maltose are present.
Protease digest proteins into amino acids
Lipase digests lipids into fatty acids and glycerol.
Maltase digests maltose into glucose.
Amylase digests starch into maltose.

Absorption of the broken down digested food into our blood stream occurs in our small intestine.
The large intestine absorbs water.
The undigested food is stored in the rectum where it is then released through the anus as (yes, poo and all that -.-) excretion. :) (Just remember to eat vegetables then you'll follow this too :D)

2.27 - understand the processes of ingestion, digestion, absorption, assimilation and egestion.

Ingestion - Occurs in our mouth (eating basically -.-), chewing with our teeth and salivary glands. Mucus also added for lubrication, amylase in saliva which begins to digest starch into maltose.

Digestion - Small intestine and some in the stomach, stage in which insoluble food particles are broken down to become soluble into our blood stream, achieved by enzymes.

Absorption - Small intestine. Structures like villi and micro villi which line the small intestine and absorb the soluble food particles into our blood stream. Gut -> Blood

Assimilation - Tissues and organs. Digested food in the blood is diffused into the cells for use (active transport). (eg. glucose for respiration)

Egestion - Rectum, anus (large intestine). Removal of waste undigested food from the digestive system (Yes. POO again.)


2.28 - explain how and why food is moved through the gut by peristalsis.

Partially digested food moves through the gut to the intestines via peristalsis.
-Muscle movements and contractions which push 'em down.
SUPER DETAIL INTO THE MOVEMENT OF FOOD DOWN YOUR GUT -Hopefully down and not back up...I wonder how you puke ._. oh!! Actually, how do you puke?
http://www.youtube.com/watch?v=7VMFL_jzFJQ

(...omgosh...if you actually look through vids of explanations of this -.- some people say it's like doing a number 2  -.- yes, excretion of solid waste through your you-know-what. EWWWW -.-" And this is why bio just ... isn't my thing -.- )

*pukes*


2.29 - understand the role of digestive enzymes, to include the digestion of starch to glucose by amylase and maltase, the digestion of proteins to amino acids by proteases and the digestion of lipids to fatty acids and glycerol by lipases.

*similar to 2.6

2.30 - understand that bile is produced by the liver and stored in the gall bladder and understand the role of bile in neutralizing stomach acid and emulsifying lipids.

emulsification increases the surface area of lipids allow lipase to digest faster.

2.31 - describe the structure of villus and explain how this helps absorption of the products of digestion in the small intestine.
1. Increase surface area for faster rate of absorption.
2. Small diffusion distance (fast) the molecules -glucose, amino acids, glycerol and fatty acids - (blue) are just a short distance away from the bloodstream (red), since the villi lining are one cell thick.
3. Concentration gradient. Blood flow keeps the concentration of the molecules in the blood stream low as blood flows past this makes the diffusion rate higher.

Help with absorption of lipids with the LACTEAL, it collects the lipid before it's returned to the circulatory system.

2.32 - describe an experiment to investigate the energy content in a food sample. The equation used to calculate the energy content of food is: energy (joules per gram) = (final temperature - initial temperature) x 20 x4.2 (joules)/mass of food (g) This is the simple experiment that we did to calculate the energy content of food.

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AFTER THE TEST:

The small intestine absorbs amino acids.

Peristalsis is important.

Pepsin is a protease enzyme found in the stomach.

Hydrochloric acid is stomach acid, found in our stomach.

Bile emulsifies the fat breaking it down into smaller pieces to increase surface are fir a faster rate of diffusion.

Bile also neutralizes stomach acid (link to importance +why?) create correct pH for lipase.

-Happens in the small intestine.

NOT ALL the starch is broken down in the mouth.

Glucose is absorbed into the bloodstream through the villi by diffusion.

It is a good idea to leave apparatus for a few minutes at different temperatures before counting the bubbles to build up enough gas and allow adjustment to the temperature change.