Cellular Energy Review Mrs. Pittaluga 8 th Grade Science Waynesville Middle School

Types of Cells ▪Prokaryotes ▪Simple, single-celled organisms (like bacteria) ▪No defined organelles ▪No nucleus ▪Eukaryotes ▪Complex organisms - plant and animal cells ▪Multiple defined organelles; need to perform cellular respiration to get energy ▪Have a nucleus

Key Cell Structures and Functions ▪Cell Membrane Forms the outside boundary that separates a cell from its environment; Controls what enters and leaves a cell; made up of lipids ▪Ribosomes Small cellular structures created in the nucleolus that are the site for protein production ▪Mitochondria Converts energy in food molecules to energy the cell can use to carry out its functions; location of cellular respiration ▪Chloroplasts Found only in plant cells; uses chlorophyll to convert the sun’s energy into glucose through photosynthesis.

Organic Compounds ▪All organic compounds contain carbon. ▪Primary organic compounds in cells: Carbohydrates – Energy-rich compounds; made up of carbon, hydrogen, and oxygen in a 1:2:1 ratio; Sugars and starches Lipids – Energy-rich compounds; store energy; provide insulation; fats, oils, and waxes Proteins – Large organic compounds composed of amino acids; made up of carbon, hydrogen, oxygen, and nitrogen; enzymes are made of proteins; meat, eggs, fish, nuts, and beans Nucleic Acids – Contain the genetic information for an organism; DNA and RNA; building blocks are nucleotides

Photosynthesis ▪The process by which a plant cell captures energy in sunlight and uses it to make food. ▪Stage 1: Chloroplasts in plant cells capture energy from sunlight ▪Stage 2: The captured light energy is used to produce sugars and oxygen from water and carbon dioxide ▪The photosynthesis equation: ▪Sun’s energy + 6 CO H 2 O → C 6 H 12 O O 2

Cellular Respiration ▪The process by which cells, plant and animal, obtain energy from glucose as long as oxygen is present. ▪Stage 1: Molecules of glucose are broken down through glycolysis into smaller molecules in the cells cytoplasm. ▪Stage 2: Takes place in the mitochondria where the small molecules are broken down into even smaller molecules and generating ATP (cellular energy). ▪Cellular respiration process: glycolysis → Kreb’s cycle → electron transport chain ▪The majority of the ATP is generated in the electron transport chain. ▪The respiration equation: ▪C 6 H 12 O O 2 → 6 CO H 2 O + energy (ATP)

Photosynthesis vs. Respiration ▪Opposite processes – products from one reaction are the reactants in the other. ▪Autotrophs are organisms that make their own food using the Sun’s energy through the process of photosynthesis; plants and some single-celled organisms ▪Heterotrophs are organisms that rely on food from other sources; animals

Types of Respiration ▪Aerobic respiration uses oxygen ▪Long-term energy (running a marathon) ▪Anaerobic respiration does not use oxygen ▪Short-term energy (running sprints) ▪Fermentation is respiration that occurs without oxygen ▪Alcoholic fermentation – ethyl alcohol is a byproduct; occurs in yeast ▪Lactic acid fermentation – lactic acid is a byproduct; occurs in muscles that haven’t gotten enough oxygen

Digestion ▪Mechanical Digestion ▪Breaking up food through chewing, tearing, crushing, squeezing, etc in order to increase the surface area ▪Chemical Digestion ▪Breaking up molecules of food through the use of enzymes

Putting the Pieces Together 1.Using the following key terms, create a concept map showing how everything we have learned in this unit is related. Make sure you show where all of the energy starts. You should also include color and pictures. PhotosynthesisCarbohydratesCytoplasm RespirationProteinsChloroplasts GlycolysisLipidsRibosomes Kreb’s cycleNucleic AcidsMitochondria Mechanical digestionEnzymesAmino acids Chemical digestionLactic AcidATP GlucoseAnaerobicAerobic Carbon dioxideOxygenWater Advanced Science Only

Putting the Pieces Together 2.Using the concept map you already created, write a one- page story showing the life of a food molecule from it’s creation in photosynthesis to the point where it used in cellular respiration. a)You must include at least 10 of the words from your concept map. b)The story should be at least one notebook page in length. c)The story should be written from the point of view of the food molecule. d)BE CREATIVE!! Advanced Science Only