Biology

It’s been said that Biology, the stify of life is the study of reproduction, and trying not to die.

It’s been said that Chemistry is the fundamnetal building blocks of Biology, some may say Bio-chemistry.

WHat is life?

People have debated what life is. The ablit to reproducv light has beeen on variabl, the ablity to choose. People have commonly used the examples that a horse and donkey can have an offspring the mule, which can’t repdrocuve, so the ablity to reproduve is not one thing lloked at. If any action i made he hav the ability to respond ot stimulus, or it’s said the ability to respond an dreact to ehe envrionment is a ofrm os snesivitiy.

Every living organism excretes, or removes it’s waste products in the form of nitrogenous compounds? Living orgnisms respirate, turn nutrition or food into energy, and grow and develop.

Generally plants move to find food and keep away from predators. Platns move towards light.

SYSTEMATICS ? & TAXONOMY

Organisms are classified if living, and non living, and named. The diversification both past and present is sorted. Systematics is basically used ot understand the evolutoinary history of lifeon earth.

CARBON

The name carbon comes from the Latin word “carbo” meaning coal, or charcoal. In French “charbon” means charcoal.

Carbon is the foundation of organic chemistry, and considered the basis of life on earth. It has the atomic number of 6. It has four electrons available for bonding. It has three isotopes: carbon 12, carbon 13, and carbon 14.
It is believed that Carbon is the fourth most abundant element in the Universe by mass after hypdrogen, helium and oxygen. It’s considered abundant in the Sun, stars, comets, and the atmospheres of most planets.

It is the second most abundant element in the human body by mass after oxygen.

It’s electron configuration is 1s2 2s2 2p2, with four electrons in the valence shell. Due to it’s four missing electrons in it’s valence shell it can combine with many things. Some of things it likes to combine with is hydrogen, oxygen, phosphorous, nitrogen.

Carbon when combined with oxygen can be dissolved in water.

WATER

Water is the fluid of most living organisms on Earth. It is vital for all forms of life. Water comes from Old English “waeter. It’s frequently dubbed the “universal solvent”. Since in the wate rmolecule the oxygen atom has a higher electronegativity than the hydrogen atoms.

Henry Cavendish showed that water was composed of oxygen and hydrogen in 1781. The study of water on earth is called hydrography, which is about 70% of the earth’s surface, with 95% of it being in the oceans.

Water is two atoms of hydrogen, and one atom of oxygen being h20 with the oxygen having a slightly negative charge, and the hydrogens a slightly positive charge.

The hydrogen atoms have a slight positive charge, and the oyxgen atoms have a slight negative charge meaning, the hydrogen of one h20 unit sticks to the oxygen in another molecule meaning all the molecules of h2o tend to stick together. This is called “hydrogen bonding”.

Water has the strongest attraction of any non metallic liquid. The way water droplets hold together is called “cohesion” which means when particles of the same substance stick together. There are some surfaces which water prefers to stick to, one example being adhesion. Water will spread out on glass, and this is called adhesion, because adhesive forces between the water and the glass are stronger than the cohesive forces between the water molecules.

Capillary action is the ability of water to go up against gravity in narrow spaces such as up in a glass dropper as the adhesive force between the water and the glass dropper is stronger than the cohesive force bewteen the water molecules, hoever the cohesive action of the water molecules draws more water up and into eventually filling the dropper. It’s believed this was first observed by Leonardo Da Vinci.

Water when freezes turns into the solid we call “ice”. Ice floats on the surface of the water because it is less dense than water, hence takes up more space.

For the life of humans people have debated how much water is needed for life. This estimation has varied greatly, although we know activity, temperature, humidity and other factors all play a role. It’s estimated the kidneys can excrete up to one litre of water per hour. The heavier water displaces the lighter ice.

Water also has heat capacity which is why it is commonly used for heating and cooling.

Water has a high surface tension, which is caused by the strength of the bonding of the hydrogen molecules between water molecules. This allows insects to walk on water.

Water is believed to tbe the most abundant molecule in the universe, and the third most abundant in the inverse after h2 and co (carbon monoxide).

Water can act as an acid or base (alkaline) in reactions. Some people think of an acid as being a proton donor, and a base as a proton acceptor.

Substances that dissolve in water are called “hydrophilic” meaning they have an affinity for water. They are polar, their polarity is stronger than the cohesive forces in the water so instead of bonding to each other the water will bond around these substances.

When something is hydrophobic, it doesn’t have an affinity to dissolve in water. They are not polar, they don’t have charged poles. The water’s cohesive forces is stronger

BIOLOGICAL MOLECULES

Biolegical molecules, or materials are a term for molecules that are present in organism essenetial for bioligical process or processes. People typically think in humans of the macro molecules proteins, carbohydrates, lipids and nucleic acids.

Oxygen, carbon, hydrogen and nitrogen make up 96% of the body’s mass. We think of biological molecules as being an essential source and storage of energy, and providing the various materials living organisms need for vital processes, that structural and functional things can be assembled.

William Prout was an English Physician and chemist. He originally ha “Prout’s hypothesis” which we now know as being incorrect. The hypothesis that hydrogen is the fundmanetal particle that other atoms were based on. It turned out to be incorrect. Ernest Rutherford partly named the proton after him. Prout published forty papers, and five booksm in 1817 he isolated purified urea ( CO(NH2)2 ), the nitrogenous waste product from the urine.

Urea
It is the main nitrogen containing compound in the urine of mammals.
Carbon, nitrogen, oxygen and hydrogen can slo be contained in human urine.

William Prout originally recognised fat (“oily”), protein (“albuminous”),

Most animals including humans have excretory system for eliminatio nof soluble toxic wastes. In humans we remove soluble wastes primarily through the urinary system, and to a lesser extent via perspiration. The urinary system in humans contains the kidneys, bladder, urthera and ureters. The constitutents of human urine is usually > 90% water in addition to inorganic salts, organic compounds, proteins, hormones and other metabolites of the body.

Out of solids in urine urea is the largest containing more than 50% of the total. It was discovered in 1828 that urea can be produced from inorganic starting materials which was significant at the time. It was the first time a substance was synthesised in a laboratory which was a by product of life, which killed the doctrine of vitalism, which believe the chemicals of life could only be produced by living organisms themselves.

Interestingly some soil bacteria possess an enzyme “urease” which convertes urea to ammonia, or ammonium ion, and bicarbonate ion.

Other contributions Prout made to our knowledge is the discovery of hydrochloric acid (hcl) as the primary acid in gastric juice, and iodine as a potential remedy for goiter, after iodine salts was found in various marine life forms, after burnt sponge which is a marine life form was used at the time for goiter.

Carbohydrates

Carbonhydrate is a synonym for saccharide (saccharide comes from the Greek word sakkharon meaning sugar) which includes sugars, starch and cellulose. The simplest of these is called glucose. There is also fructose which has the same chemical formula as glucose, but is arranged differently.

There are things called disaccharides which is as the name implies simply two sugars joined together. Sucrose being probably the most well known example which is a glucose and a fructose joined together.

Poly saccharides can be thousands of sugar units joined together. Cellulose is the most common structural compound in plantsa polysaccaride that can contain hundreds or thousands of carbon, hydrogen and oxygen atoms. It is the main copnent in walls of plant cells. Humans cannot digest cellulose.

Mono and di saccarides are considered easier for the body to process than their more complex counterparts.

Startch is a carbohydrate conisting of glucose units. It’s the most common carbohydrates in thehuman diet. It consistens of amylopectin, and amylose.ts.

Humans tend to store glucose in the form of glycogen.

Fats

Lipids are smaller and simpler than complex carbohydreates, There ponds are mostly non polar which means they have a difficult time dissolving in water. Fats are mainly made up of glycerol, and fatty acids. Three fatty acid molecules connected to three glycerols this is called a “triglyceride”. So fatty acids, and glyercol are the building blocks of triglycerides.

Saturated and unsaturated fatty acids – saturated with carbon?A saturated fat is a type of fat where all the fatty acid chains have all or predominatly single bonds.
An unsaturated fat has at least one double bond in the fatty acid chain.

There’s also phopholipids, one end is attracted to water (polar), the other non polar end avoids water. Cholesterol binds with phospholipids to help build cell walls. They can also be activated to turn into lipid hormones. Estradiol, and testosterone being an example.

Proteins

Proteins are comprised of amino acids. Some are considered essential, some are not considered essential. They are comprised of a carboxyl (COOH) group, an amino group (NH2), and what’s called an R group, which is a variable number for a number of groups that can bond. An R group is sometimes called an “side chain”, and whatever connects to the molecule where the r group is will determine the shape and function of that molecule.

Amino acids form long chains called poly peptides. There are nine essential amino acids because it’s considered we can’t make them ourself.

The essential amino acids are:

Histidine
Isoleucine
Leucine
Lysine
Methionine
Phenylalinine
Threonine
Tryptophan
Valine

CELLS

The buliding blocks of living organisms is cells. Humans have trillions. Our cells are called eukarotic? spelling, because they have “a true kernel” in Greek, or nucleus. It was Robert Hooke in 1665 with a microscopewho discovered and named the cell. It was named after “cellula” which looked like small rooms that monks inhabited.

In contrast with prokaryotic, which means before the kernel ? they don’t have a nucelus ?

Theodor Schwann, and Matthais Schleiden studied animal and plant cells and summarised their conclusions that cells are the structure, organisation and physiology of livining things. Also, the cells has a dual existence as a distinct eneity, and a building block in the construction of organisms.

Later on it was discovered that cells form through division. It was Rudolph Virchow who said “all cells only arise from pre existing cells.”

Plant cells wall are made from cellulose which makes them more rigid tham human cells which are made from fat / lpid? The wall is called a membrane. The fact that some things can pass through the cell wall called permeability, that facts that only some things can go in and out of the cell wall is called selective permeableility.

The water and nutrients in the cell is called the cytoplasm, it contians he water and nutrients in the cell, and the cyto skeleton,.

organelles ?

Centrosomes give the cell structural support?

The centre of the nucleus is called the nucleoplasm?

Endoplasmic reticulum they are made from phopholipid bilayers? There is a rough and smooth er. It contains enzymes which help in the creation of lipids.

The lysosome break down waste in the cell using enzymes.

The nucleus stores the cells dna. dna in cells?

THe dna is held in the nucleus in a substance called chromatin. Humans have 46 chromosomes choromsones and chromatine relationship ? The number of chromosones varies amoungast animals.
The smmoth er stores ions such as sodium ? which the cell may need later on ?

The nucleolus ? makes rna

The m rna or the messenger rna is sent to the ribosomes ? to carry out the orders.

The mitrochondria ? has been compared to the powerplant of the cell.

The rough er helps in the packagining of protein ?

Ribosomes assemble amino acids into poly peptides

The golgi appartus is like a post office, processing and packaging protein. In the golgi appartus is something called golgi bodies. From this the body then makes vessicles ? which have phopholipid membranes

protozoa, flagellum, cilia

MEMBRANES

The walls of cells need to be selective permeable. That means they need to be selective about what they let out and in.

osmosis diffusion concentration

osmosis the fact that something moves through a membrane so there is equal pressure on either side of the membrane. Think of it being like crowded peopl ei n an elevator, as saoon as the doors open the people rush out. Basically it moves from more crowded places to less crowded places.

If the concenrtraion of a solution i shigher inside the cell than outisde then that is called hypertonic. If it’s higher outside the cell than inside then it’s called hypotonic. When water moves from a place of higher concentration to lower concentration it’s called moving across it’s concentration gradient.

Aquaporins in cells?

If something has to move from a low concentration to a high concentraion that’s called active transport. ? High energy transport is moving something in reverse of the concentration gradient ? Most cells ? have something called a sodium – potassium pump.

excocytosis ?

pinocytosis how cells absorb nutrients ?

Vesicular transport is done by vesicles

This works against both the electro chemical gradient and the concentraiton gradient ?

The kidneys are constantly trying to regulate th eblood plasma to make it isotonic ?

When it’s equal inside and out of the cell it’s called isotonic?

There’s two ways to cross the cell membrane: active transport & passive transport. ?

Passive transport is easy for things like oxygen and water to get in and out of the cell.

PLANT CELLS

Plant cells convert carbondioxide from the air and convert it into oxygen for us to breathe. when did plants evolve? lycophytes? carboniferous period

plants exist by shedding spores

angiospores ? eggs in plant? to repsorduce

cretaceous period ?

organelles ?

The cell walls of the plant are made out o fcellulose and lignan ? which is very strong

Plants make their food through photo synethesis ? needing sunlight and water ? what aspect does soil play ?

plastids ?

chloroplasts are the most important of the plastids. They are only found in plant cells, not animal cells.

Plant cells have central vacuoles?

Mesozoic period is 252 – 66 mya broken into triassic (252 – 201 mya), jurassic (201 – 145 mya), cretaceous (145 – 66 mya)

they use light into sugar and oxygen ?

vaciules contain water ?

ATP

Glucose is considered the foundation of energy, and it is believed that glucose when combined with oxygen is the foundation of energy. When oxygen combines with glucose it releases up to 38 molecules of atp? this is called cellular respiration ?

Glucose is transofmred into ATP through three stages: glycolysis, the krebs cycle, and the electron transport chain.

Thikn of glycolysis as being the break down of the glucose. Glycolysis occurs in the cytoplasm, the liquid medium within the cell. Glucose breaks down into two three carbon molecules called pyruvic acids, or pyruvate molecules.

GLycolysis uses two ATP’s for a result of four ATP’s ?, in addition to two pyriuvates, and NADH.

Glucose (C6H1206) + 6 x 02 (oxygen) > 6 CO2 (carbon dioxide) + 6 H20 (WATER) + ENERGY

Adenosine triphosphate, sometimes referred to as bioligical energy, or the currency of the cells, is comproised of adednine which has a nitrogensous base, a sugar called ribose and 3 phosphate groups attached hence the name tri.

Adenosine diphostate is where one of the phosphate groups is not on the end of thr group, but rather a hydroxide takes its place?, basically the “di” means there are two phosphate groups. When ATP converts to ADP energy is released.

HYdrolysis means reation with water. When ATP + H20, when ATP reacts with water, it creates ADP + P ?

We take a monomer and convert it to a polymer ?

nucleotides becomes a polynucleotide chain ? A nucleotide is composed of a sugar, and a nitrogenous base, with a phosphate group. In ATP the three phosphate groups are covalently bonded.

The electrons in the three phosphate groups are energetically unstable?

The phosphate groups have been phosphorilised which means there’s only two groups less.
eventually a hydroxide group replaces the third phosphate ?, or adenosine monophosphate.

ATP is classified as a nucleoside triphosphate, it has three components (adenine (nitrogenous basea), ribose (whic his a sugar), and triphosphate.

ATP provides energy to a reaction by donating one of it’s phosphate groups.

In an absense of oxygen, the glycolysis can go on in an anaerobic process called fermentation. In yeast the product of fermentation is ethyl alcohol?

When the muscles use all the oxygen they can get they then go into anareobic respiration generating lactic acid.

The next stage of the atp cycle / cell cycle ? is the krebs cycle, and the electron transport chain ?. They’re aerboic processes. After glycolysi s? is the kreb’s cycle.

The krebs cycle takes two pyruvate molecules and creates 2 atp per glucose molecule.

GLYCOLYSIS

Glycolysis is the matabolic pathway that converts glucose (C6H12o6) into pyruvate (CH3COCOO- (pyruvic acid) and an hydrogen ion H+. Think of the word “lysis”, or “lysing” or “lycing” as being cutting.

The process begins with glucose (C6H12o6). The next step is the six carbons are broken into two three carbon compounds. A phosphate group attachs, this is called phosphoglyceraldehyde, or PGAL.

In the nexk phase called the “pay off phase”, the PGALs are turned into pyruvate, or what’s sometimes called pyruvic acid. FOr every molecule of glucose you start off with you end up with two molecules of pyruvate.

KREB’s cycle
, or “tricarboxylic”” acid cycle.
The kreb’s cycle is sometimes called the “citric acid” cycle. Sir Hans Adolf Krebs who fled Nazi Germany to serve at ambridge / Oxford ? discovered teh citric acid cycle, and the urea cycle. With Hans Kornberg he also discovered the glyoxylate cycle which ia a variation of the ctiric acid cycle found in plants, bacteria and fungi.

The carbon dixodide waste product of the kreb’s cycle is being exhaled by humans through the lungs.
The kreb’s cycle happens inside and around the mitochondria. If you receall mitochondria is often considered the power plant or generator of the cell. The kreb’s cycle take the pyruvate molecules.

When pruvate oxidises or combines with oxygen. One of the carbo leaves the cell with o2 (molecular oxygen) as CO2 (carbon dioxide). The 2 carbon molecule left is called acetyl coenzyme A or aceytal coA

THen NAD combines with H+

NAD+ and FAD are enzymes ? whne comnbined with hydorogen becomes NADH and FADH2

ELECTRON TRANSPORT CHAIN

The NADH and the FADH made in the Kreb’s cycle

The electrons are sent from the inner compartment of the Mtiochoodnria to the outside?

Atp synthase proton flow?

PHOTOSYNTHESIS

When plants grow they will bend to the light. The stem grows up, and the roots grow down.

“Tropism” is a phenonmemon of biology indicating growth toward or away, basically in reaction to an environmental stimulus. Water and light are vital for a plant to photosynthesise so it has mechanisms to ensure it can maximise uptake of these.

Think of a tropism as being a reaction. In plants light (phototropism), gravity (geotropism) water (hydrotropism), and touch may all play a factor.

Positive tropism is when the plant grows towards the stimulus, and negative tropism when the plant grows away from the stimuls. It’s generally accepted the stalk grows towards the light (phototropism), and the roots grow downard. (gravitropism)

Photo synthesis is the process of converting sunlight, water and carbon dioxide into glucose and oxygen. Is it human respiration in reverse?

The formula for phto sysnthesis is carbon dioxide + water + light > glucose + oxygen ? (is it light on chlorophyll?)

A vacular system in plants wouild transport the food, and water.

Xylem moves water and solutes from the roots to the leaves.

The phleom moves the glucose and amino acids made in the leaves? to the rest of the plant.

The phleom can move both ways where as the xylem can only move one way ? It uses active transpo osmois diffusionrt. Glucose is oconverted into sucrose in the “sources” of the plants. in the leaves ?

These two transport systems look different in the stem and the roots.

chloroplats producxe sugar

guard cells

stoma
Root have hairs which give them a large surface area for water aborbtion.

Le chatelier’s principle

Gibbs free energy

SEXUAL REPRODUCTION IN PLANTS

Petals are the leaves that aurround the repdoructive parts of flowers.

Sepals are the protection for the flower when in bud, and used as support fot the petals.

Where the stem meets the flower is called the receptacle. The stamen is the male part of the plan that forms out of th eflower like antennas?
The filament supports the anther on the end, together they are called the stamen.. THat is the male part of the plant

The carepl is the female part of the plant. The end of the carpel is the stigma, the style is the long vertical part coming out of the carpel. The ovary is located at the nbottom end of the style.

Pollenation is the transfe of pollen from the male anter otf one plant to the female stigma of another.

Wind and water can move the pollen, or pillinators can move the pllen such as insects and birds.

THe flower looks different based on if it’s received the pollen from wind and water, or a pollinator. Once a plant has been pllinated ferilisation occurs resuling in seeds being produced.