Acids, bases and buffers

An acid has a pH between 0 and 6.9. It turns litmus paper red, an easy way to think of this is by the stomach is red and the acid inside the stomach is very acidic. Acids are very corrosive. When you add an acid to water the acid adds more [H+] ions making the solution have a lower pH. For example, HCl--> H+ + Cl- 

A base has a pH between 7.1 and 14. It turns litmus paper blue. Bases are caustic and a way to tell it's a base is that they are slippery. When you add a base to a solution it will remove [H+] ions. This is because the base separates when it hits the solution and the OH pair up with an [H+] forming a water molecule, making the soliton have a higher pH level. An example is:    NaOH --> Na + OH then the OH connect with a H+ forming H2O.

 

A neutral solution is where the acids and bases are balenced (equal).

Buffers either absorb or give away an H+ ions until it is overloaded. Overloaded means that it can not take or give away any more H+ ions. When it is in an acidic solution, a buffer will absorb H+ ions. For example, H+ + CO3 2-  ---> HCO3 1- .

When it is in a basic solution, a buffer will donate H+ ions. For example, OH- + H2CO3 ----> H(OH) + HCO3 1-  

Usually a buffer has 3 or mot 'versions' of itself.

Why is water so unique?

The reason for water being different from many other cells is because water has a special type of bond called a polar covalent bond. This means that the electrons are shared throughout the molecule unequally.   

In addition, because the electrons spend more time surrounding the oxygen atom, the oxygen has a negative charge, and the hydrogenation have a net positive charge. That's why it is polar. Two polar molecules attract to each other and form a lattice. Water molecules are connected together by hydrogen bonds. Hydrogen bonds are weak in small numbers but lots of them together they are very strong, making water very stable. 

Another interesting fact is that a lot of energy is needed to break a water lattice, making it have a wide temperature range that water is stable at which is 0-100°C. The final unique thing that I know about is that is occurs naturally in three states of matter( liquid, solid and gas).

Some of the properties of water are surface tension. The water molecule are cohesive meaning they sick together. This is why you can fill a cup past the "full" point. Like in this picture.

Another property is capillary Action. This is where water is sucked up a small tube against the force of gravity because the water molecules are cohesive and adhesive so they sick to themselves as well as the outer surface.

Heat and vaporization is anothe property of water. This means that a lot of energy is needed to break water lattice apart making water stable over a wide range.

Ionization of water is a property of water. When the attraction is greater for something else, the hydrogen bonds will break and tear water molecules apart. This causes oxygen and hydrogen to dissociate into ions. H2O ---> H+ +  OH-

Finally the last property is the solvent properties, it can dissolve any ionic compound.  The polarity of water molecules will break the bonds between ionic compounds and the slightly positive hydrogen attract the negative ions and vise versa. 

Cell structure

   

There are lots of different parts in a cell. The cell is surrounded by a duel layer called the plasma membrane or phospholipid bilayer. Inside the cell there is a nucleus, its job is to store genetic information like chromosomes and it also controls the cell activity through protein synthesis. The nucleus is like a brain. Inside the nucleus there is the nucleolus which is the dark centre of the nucleus made up of RNA. Its rRNA's make ribosomes and send them out through the nuclear envelope. Ribosomes are where protein are made and they also make sure the amino acids are in the correct order. The role of the nuclear envelope is to let RNA and protein in and out of the nucleus through its pores. The last thing in the nucleus is the nucleoplasm. This is pretty much the same as cytoplasm but inside the nucleus, it is a jelly like substances that supports and suspends the contents of the nucleus. Next thing in a cell is the mitochondria. It acts like the furnace of the cell, converts the chemical energy in food to ATP, cellular respiration. Next is the endoplasmic reticulum, which is the rough ER and the smooth ER. The rough ER transports proteins and sometimes modifies them, it packages the protein up in a vesicles and sends it to the Golgi body.  The smooth ER transports hormones and fats and makes lipids and steroids, it detoxifies harmful material or waste products. The Golgi  body receives, modifies and temporarily stores the proteins and fats from the smooth and rough ER. It also makes lysosomes. Lysosomes are sometimes known as "suicide sacs", they attach to food vacuoles and digest their contents. They can also destroy old or malfunctioning cell parts. Vesicles and vacuoles are storage sacs of the cell membrane it transports substances around the cell that needs to be separate form the cytoplasm. They cans stir food, water and/or waste. The difference between a vacuole and a vesicles is that a vacuole is just bigger. The thing that makes the cell have its shape is the cytoskeleton. It acts as a frame work. Microfilaments are long and externally thin protein fibres that occur in bundles made up of two proteins called Actin and Myosin. The microfilaments help organelles move around the cytoplasm. The other structure you might confuse this with is the microtubules. They are pretty much the same thing but bigger and cylinder shaped made up of coiled protein called tubulin. Microtubules are used to make cilia, flagella and centrioles. Cilia are tiny little hairs and are used to produce locomotion. Flagella is found in sperm cells. Centrioles attach to and move chromosomes during mitosis. Finally, those are all the organelles of the cell that I know and what they do.

You may ask how does a cell make a protein.. Well your in luck cause I am here to tell you how! First,it all starts of with the nucleus. The nucleus makes ribosomes and sends them out the nuclear pore. Some ribosomes attach to the rough ER and makes the protein, sometimes it modifies the protein then it stores the protein. When the protein is ready it sends it to the Golgi body in a vesicle. In the Golgi body the protein is modified and the enzymes are activated and sends it to the plasma membrane, released via exocytosis. The end. 

This is the plasma membrane model I made.

This is the Golgi body you can tell because if the flattened pancake shapes that are all together and the vesicles (round dots) around it

Homeostasis

One thing i now know that i probably wont forget is the differences between positive and negative feedback loops. A positive feedback loop only stops when something occurs and a negative feedback loop shuts itself. 

Homeostasis keeps the body on track. Sensitive receptors monitor each condition under the homeostatic control. It monitors temperature, blood pressure, surcharge levels, osmolarity, PH and etc. If these are not in  the balanced range then the feedback loops kick in, called the corrective mechanism, which reverses the original change and brings the system back to normal. How this all works is the first thing is the stimuli, for example the body temperature rises above 37.5 degrees Celsius. Then the receptor detects it and sends a signal to the regulatory centre. Then the regulatory centre send that message to the effector, which is usually a muscle or a gland. Finally the response happens, for example sweat if its too hot. The body becomes normal again and if the feedback loop was a negative one it would shut off. This all happens continuously as we live our lives. An example of a positive feedback loop is labour. 

There is our poster we made...