Cell Transport and Biochemistry

Day 2

Cell Transport-Passive Transport

• Passive Transport: does NOT require energy• Molecules move from an area of high concentration to an area

of low concentration

• 1. Diffusion: substances move directly through the cell membrane• 2. Facilitated Diffusion: uses channel proteins to move a

substance through the cell membrane• 3. Osmosis: The movement of WATER from an area of

high water concentration to an area of low water concentration• Can occur in either direction

Cell Transport-Solution Concentrations• Solution Concentrations:• Hypotonic: solution has lower concentration of solute---higher

concentration of water• Cell Swells

• Hypertonic: solution has a higher concentration of dissolved solute---lower concentration of water• Cell Shrinks

• Isotonic: net concentration of dissolved solutes are the same inside and outside of the cell.• Cell remains the same

Cell Transport-Active Transport

• Active Transport: Requires energy• Movement of substances from an area of low concentration to

an area of high concentration• Occurs against the concentration gradient

• 1. Exocytosis: removes materials from the cell• 2. Endocytosis: Brings materials into the cell

Chemistry in Biology

• The basic unit of matter is the atom• The subatomic particles that make up atoms are protons,

neutrons, and electrons• Protons and Neutrons have the same mass• Protons have a positive charge• Neutrons have no/neutral charge• Protons and neutrons are located in the nucleus• The electron has a negative charge• Electrons are located outside of the nucleus in the electron

cloud

Acids, Bases, and pH

• The pH scale is a measurement system that indicates the concentration of H+ ions in a solution• pH ranges from 0 to 14• Pure water has a pH of 7• Acids range from 0 to 6.9• Bases range from 7.1-14

Carbon Compounds

• Many of the molecules in living cells are very large. They are known as Macromolecules• The four groups of organic (carbon containing)

compounds found in living things are:• Carbohydrates• Lipids• Nucleic Acids• Proteins

Carbohydrates

• Made up of Carbon, hydrogen, and oxygen atoms• Living things use carbohydrates as their main source of

energy• Single sugar molecules are called monosaccharides• Large macromolecules made from monosaccharides are

known as polysaccharides

Lipids

• Generally not soluble in water• Made up of Carbon and hydrogen atoms• Common categories of lipids are fats, oils, and waxes. • Lipids are used to store energy

Nucleic Acids

• Made up of oxygen, nitrogen, carbon, and phosphorus• Nucleic Acids are polymers made from individual monomers

known as nucleotides• 3 parts of a nucleotide

• 5-Carbon sugar• Phosphate group• Nitrogenous base

• Nucleic Acids store and transmit heredity or genetic information• 2 kinds of Nucleic Acids

• DNA• RNA

Proteins

• Made up of nitrogen, carbon, hydrogen, and oxygen• Proteins are polymers of a molecule known as amino

acids• Protein Functions:• Control the rates of chemical reactions (enzymes)• Regulate cell processes• Form bone and muscles• Help fight disease• Transport substances into and out of the cell

Enzymes

• Proteins that act as biological catalyst are known as enzymes• Cells use enzymes to speed up chemical reactions• Enzymes work by lowering the activation energy of the

biological reaction