Chapter 3 Cell Processes

Chemistry of Life Everything-made of matter and energy –matter- anything that has mass and takes up space –energy- holds matter together or breaks it apart

Chemistry of Life-cont. Matter –made of atoms nucleus contains protons and neutrons electrons are outside the nucleus

Chemistry of Life-cont. Elements –made of one kind of atom cannot be broken down into a simpler form by an ordinary chemical reaction arranged in the periodic table of elements

Chemistry of Life-cont. Compounds –made of two or more elements –have different properties from the elements they are made of –smallest part of a molecular compound is a molecule –molecule-group of atoms held together by the energy of chemical bonds –form when atoms share electrons

Chemistry of Life-cont. Ionic compounds –ions-electrically charges atoms positive or negative electrically neutral- ions of opposite charges attract one another.

Chemistry of Life-cont. Mixture-combination of substances –solution-two or more substances are mixed evenly –suspension-forms when a liquid or gas has another substance spread throughout it

Chemistry of Life-cont. Organic compounds-contain carbon or hydrogen –carbohydrates-supply energy for cell processes –lipids-store and release large amounts of energy –proteins-building block of many structures amino acids enzymes –nucleic acids-stored coded information in cells

Chemistry of Life-cont. Inorganic compounds –usually made from elements other than carbon

Chemistry of Life-cont. Importance of water –living things-composed of more than 50% water –all chemical reactions take place in water solutions –most living things use water to transport materials

Moving Cellular Materials Cells have a permeable membrane that regulates what goes into and out of a cell.

Moving Cellular Materials-cont. Passive transport- movement of substances without energy –diffusion-move away from areas where there are more of them into areas where there are fewer of them –osmosis-diffusion of water –facilitated diffusion-transport proteins move substances

Moving Cellular Materials-cont. Active transport- requires energy to move substances through a cell membrane

Moving Cellular Materials-cont. Endocytosis and Exocytosis –endo-taken into the cell –exo- released outside the cell

Energy for Life Cells use chemical reactions to change the chemical energy stored in food into forms needed. –metabolism-total of all chemical reactions –chemical reactions require enzymes

Energy for Life-cont. Photosynthesis-converts sunlight energy into chemical energy or sugars to be used as food. –producers- make their own food –consumers-can’t make their own food –chlorophyll (pigments)-capture sunlight to produce sugar and oxygen

Energy for Life-cont. Respiration- chemical reaction to break down food molecules into simpler substances and release stored energy. –begins in the cytoplasm carbohydrates are broken down into glucose molecules glucose molecules break down into simpler molecules releasing energy –continues in mitochondria two simpler molecules are broken down again, releasing more energy process uses oxygen and produces CO 2

Energy for Life-cont. Fermentation- cells that do not have enough oxygen for respiration use this process to release some of the stored energy in glucose molecules. –process occurs in cytoplasm –produces lactic acid, alcohol, and carbon dioxide as wastes

Energy of Life-cont. Photosynthesis and respiration –photosynthesis-produces sugars and oxygen, which are used in respiration –respiration-produces carbon dioxide and water, which are used in photosynthesis.