Biology—chemical reactions

Element-matter that can not be broken down into a simpler substance There are 92 known elements and all are shown of the periodic table Each element has a symbol ex. H-hydrogen Elements differ from one another by the number of protons they have (atomic number ) (example: hydrogen has 1 proton/carbon has 6 protons) Metals are on the left of the dark line/nonmetals are on the right

Chemical formula- tells the number of elements present and how many of each element example water has 2 hydrogen and 1 oxygen

Why is water so important to life? 1.Absorbs heat to keep the temperature stable 2.Good lubricant (ex. Tears in eyes) 3.Needed for reactions 4.Dissolves a lot of substances (universal solvent) ex. Water in blood transports nutrients

Organic molecules- contain carbon (except Carbon dioxide) types of organic macromolecules in humans 1.Carbohydrates 2.Lipids-fats 3.Proteins 4.Nucleic acids

Carbohydrates Composed of C, H, O Monosaccharides are the simplest units that make them up 2 monosaccharides form disaccharide many monosachharides form polysachharides

Lipids- fats Composed of C, H, O, N, P Glycerol-smallest units that make up lipids -used to repair tissue

2 types of fats: Saturated fat- all carbons have a single bond Unsaturated fat- all carbons do not have a single bond (easier to break down)

Proteins Made of C, H, O, N, S Amino acids are the smallest unit that makes them up. There are 20 amino acids putting these in different combinations results in different proteins Enzyme- protein that speeds up reactions

Nucleic acids Made of C, H, N, O, P Nucleotides-smallest unit that makes up nucleic acids There are 2 kinds of Nucleic acids: DNA (deoxyribonucleic acid) RNA (ribonucleic acid)

DNA and RNA DNA- genetic material of the cellRNA- protein synthesis -controls the cells activities(makes proteins) -found in the nucleus-found in ribosomes DNA structure– consists of a double RNA structure- consists of helix (2 strands of nucleotide1 strand of nucleotides coiled together)

2 main chemical reactions that occur in living things Photosynthesis-uses light energy to convert inorganic material to sugar. Respiration-breaks down glucose to give off energy (energy)

Photosynthesis Process used by a plant to make its own food Ingredients needed are: Carbon Dioxide (CO 2 ), water (H 2 O) and energy from sun Products are: Oxygen (O 2 ) and glucose (C 6 H 12 O 6 )

The process of photosynthesis occurs in the leaves In leaves, the carbon dioxide, water and energy combine to form glucose and oxygen

Equation for photosynthesis CO 2 +H 2 O+sun’s energy  C 6 H 12 O (glucose) We get our oxygen supply from plants because they produce it in photosynthesis!

Photosynthesis occurs in 2 phases: 1. Light dependent reaction- uses the sun and the chloroplast to convert light energy to chemical energy (ATP) 2. light independent reaction (Calvin Cycle) –does not need sunlight for this phase –takes the ATP energy and makes the glucose

Respiration In order for organisms (like animals) to have energy for their cells to function, they must: –1. ingest glucose from plants –2. convert it to a form of energy that their cells can use (ATP). The energy form that animal cells use is called ATP (Adenosine Triphosphate)

Respiration cont… The process of converting glucose to ATP is called respiration (burning of glucose) It occurs in the mitochondria of cells Equation of respiration: O 2 +C 6 H 12 O 6 (glucose)  CO 2 +H 2 O+ATP (energy)