Organic Molecules

Carbohydrates:

  • Major source of energy(short term) and include sugars and starches.

  • Made up of carbon. hydrogen, and oxygen with a 2:1 ratio of hydrogen to oxygen; monomer: monosaccharide.

  • plants and animal us carbohydrates for maintaining structure within the cells.

Proteins:

  • Nitrogen-containing compounds made up of chains of amino acids.

  • 20 amino acids can combine to form a great variety of protein molecules.

  • can compose enzymes. hormones, antibodies, and structural components.

Lipids:

  • Water-insoluble (fats and oils)

  • made up of carbon, hydrogen and oxygen; composed of glycerol and fatty acid.

  • provide insulation, store energy (long term), and cushion internal organs, found in biological membranes.

  • saturated (with hydrogen, single bonds) and unsaturated (double bonds)

Nucleic acids

  • direct the instruction of proteins

  • genetic information an organism receives from its parents

  • two types: DNA (deoxyribonucleic acid) and RNA (Ribonucleic acid)

PROPERTIES OF WATER

  • Adhesion - water is attracted to other molecules; Cohesion - water is attracted to itself; ex: capillary action-water defies gravity and moves up a tree.

  • High Heat of Vaporization - sweating to cool down.

  • Less dense as a solid than a liquid (ice floats); ex: insulate lakes so that organisms can survive during the winter.

  • water is a great solvent (good at dissolving things); ex: dissolve nutrients.

Water can dissolve salt because the positive part of water molecules attract the negative chloride ions and the negative part of water molecules attract the positive sodium ions.

Cohesive property of water in our body (capillary action) -it is the movement of water in and out of your cellular structures that deposits vitamin, nutrients and vital blood plasma.

The uniqueness of water comes from its molecular structure. Water is polar; is has a slight positive and slight negative charge and opposite ends. Oxygen- slight negative charge hydrogen- slight positive charge. The polarity of water is responsible for effectively dissolving other polar molecules. This is important to remember because for most biological reactions to occur, the reactants must be dissolved in water.

MUTATIONS

-change in genetic code

-passed from one cell to new cells

-transmitted to offspring if occurs in sex cells

-most have no effect

-Gene mutations - change in a single gene; point/substitution or insertion and deletion; occurs during during DNA replication.

-Chromosome mutation - change in many gene; occurs during cell decision.

-can be spontaneous or caused by environmental mutagens (radiation, chemicals, etc.)

  • Most mutations have no phenotype effect. these are called silent mutations, and we all have a few of these.

  • of the mutations that have a negative effect. most of the proteins in the cells are enzymes. and most changes in enzymes stops working, a metabolic block can occur, when a reaction in cell doesn’t happen, so the cell’s function is changed. An example of this is the genetic disease phenylketonuria (PKU)

  • Very rarely a mutation can have a beneficial phenotypic effect, such as making and enzyme work faster, or a structural protein stronger, or a receptor protein more sensitive. although rare beneficial mutations are important as they drive evolution.

  • A substitution on the third base of a codon may have no effect because the third base is less important.

  • If a single amino acid is changed to a similar one, then the protein structure and function may be unchanged, but if an amino acid is changed to a very different one, then the structure and function of the protein will be very different.

  • Additions and Deletions are Frameshift mutations and are far more serious than substitutions because more of the protein is altered

  • Some proteins are simply more important than others.
    For instance non-functioning receptor proteins in the tongue may lead to a lack of taste but is not life threatening, whereas non-functioning hemoglobin is fatal.
    Some cells are more important than others. Mutations in somatic cells (i.e. non-reproductive body cells) will only affect cells that derive from that cell, so will probably have a smail local effect like a birthmark (although they can cause widespread effects like diabetes or cancer). Mutations in germ cells (i.e. reproductive cells) will affect every single cell of the resulting organism as well as its offspring. These mutations are one source of genetic variation.

Mutations in chromosomes are different from gene mutations, nodification results in more marked phenotypic effects. Mutations in chromosomes occur during the formation of zygote where there are changes in the number of chromosomes: this may result in fission or fusion of chromosomes. Changes in the structure of chromosome can occur in many ways including inversion, duplication. deletion or translocation.

BIOCHEMICAL REACTIONS: chemical bonds are formed and broken within living things creating chemical reactions that impact the ability to maintain life and carry out life functions

Cellular Respiration -food molecules are converted to energy: there are three stages to cellular respiration; the first stage is called glycolysis and is anaerobic (no oxygen is required); and are aerobic (oxygen is required)

C&H1206 + 602 → 6CO2+ 6H2O+ ENERGY (36 ATP) nito Choaaria

- Photosynthesis -plant cells capture energy from the Sun and convert it into food (carbohydrates); plant cells then convert the carbohydrates into energy during cellular respiration; the ultimate source of energy for all living things is the Sun (in Chemosynthesis, organisms use sulfur or nitrogen as the main energy source)

6C02 + 6H20 + ENERGY (from sunlight) → C.H1206+602 GHoroplast

- Interrelated nature of photosynthesis and cellular respiration- the reactants of photosynthesis are the products of cellular respiration and vice versa.

ATP-ATP is a molecule that stores and releases the energy in its bonds when the cell needs it; removing a phosphate group (P) releases energy for chemical reactions to occur in the cell and ATP becomes ADP; when the cell has energy, the energy is stored in the bond when the phosphate group is added to the ADP ATP ADP + P+ ENERGY

- Fermentation -when cells are not provided with oxygen in a timely manner, this process occurs to continue producing ATP until oxygen is available again; glucose is broken down; there are two types of fermentation:

Lactic Acid Fermentation (muscle cells) Glucose → Lactic Acid + 2ATP

Alcoholic Fermentation (plant cells) Glucose → CO2 + Alcohol + 2ATP

AEROBIC and ANAEROBIC RESPIRATION:

Aerobic Respiration - 3 stages (glycolysis, Krebs cycle and Electron Transport chain)

• requires the presence of oxygen

release of energy from the breakdown of glucose (or another organic compound) in the presence of oxygen to produce large amounts of energy.

• energy released is used to make ATP, which provides energy for bodily processes

takes place in almost all living things

Anaerobic Respiration - 1 stage (glycolysis)

• occurs in the absence of oxygen

  • breakdown of food substances in the absence of oxygen with the production of a small amount of energy

  • produces less energy than aerobic respiration

  • 

  • 

often called fermentation: lactic and alcoholic

seen as an adaptation for organisms that live in environments that lack oxygen

ENZYMES:

Enzymes are special proteins that regulate nearly every biochemical reaction in the cell. Different reactions require different enzymes. Enzymes function to:

• Aid in digestion

  • Break down complex molecules ("substrate" = reactant)
    Catalysts (speed up chemical reactions without being used up or altered

  • Factors that affect enzymes: pH, temperature, and quantity

  • Lower activation energy for chemical reactions.

  • Enzymes are affected by changes in pH. The most favorable pH value - the point where the enzyme is most active - is known as the optimum pH.

Like most chemical reactions, the rate of an enzyme-catalyzed reaction increases as the temperature is raised. Most animal enzymes rapidly become denatured at temperatures above 40°C, most enzyme determinations are carried out somewhat below that temperature.

CELL TRANSPORT:

- Passive Transport - movement of substances across the plasma membrane without the use of the cell's energy (with the concentration gradient)

  1. DIFFUSION - movement of substances across the plasma membrane from an area of high concentration to an area of low concentration

  2. OSMOSIS - diffusion of water across the plasma membrane from areas of high concentration to areas of lower concentration

• HYPOTONIC - water moves in; cell bursts

1 HYPERTONIC - water moves out; cell shrivels

ISOTONIC - no net movement; cell maintains equilibrium

3. FACILITATED TRANSPORT - a carrier molecule embedded in the plasma membrane transports a substance across the plasma membrane following the high-to-low concentration gradient

- Active Transport - movement of substances across the plasma membrane that requires the use of the cell's energy and carrier molecules; substances are moving from an area of low concentration to an area of higher concentration (against the concentration gradient)

C ENDOCYTOSIS - large particles are brought into the cell

  • EXOCYTOSIS - large particles leave the cell

  • HOMEOSTASIS - internal equilibrium; the plasma membrane regulates what enters and leaves the cell; a selectively permeable membrane only allows certain substances.

Mitochondria (plants/animals) and Chloroplast (plants) - cell energy.

Rough ER- contains ribosomes;

protein synthesis

Movement; found in both prokaryotes and eukaryotes.