Chapter 3waeagles220.weebly.com/uploads/8/4/3/7/8437155/chapter_3.pdf · Chapter 3 CELL PROCESSES...
Transcript of Chapter 3waeagles220.weebly.com/uploads/8/4/3/7/8437155/chapter_3.pdf · Chapter 3 CELL PROCESSES...
Chapter 3CELL PROCESSES AND ENERGY
Section 1: Chemical Compounds in Cells
Elements= Any substance that cannot be broken down into a simpler form
◦ Made up of only one kind of atom◦ Found in the body
Carbon - CHydrogen - HOxygen - ONitrogen - NPhosphorus -PSulfur -S
CompoundsCompounds = Two or more elements chemically combined•Molecule= Smallest unit of a compound
•Compounds found in the body:• Water (H2O)
• 2/3 of the body
• Needed for chemical reactions within the cells
• Carbon Dioxide (CO2)
•Organic vs. Inorganic Compounds• Organic- contain carbon
• Inorganic- do not contain carbon
• Examples: water, table salt
Organic Compounds in Living Things
1. Carbohydrates
2. Lipids
3. Proteins
4. Nucleic Acids
Carbohydrates•Energy-rich compounds
•Two Types 1. Simple Sugars- Building blocks for starches;
includes glucose, fructose Example: fruit2. Complex- Starches
Ex: vegetables, potatoes, rice,pasta, bread
•Make up some cell parts• Cellulose is found in cell walls of plants• Carbs are also found in cell membranes
Lipids•Includes Fats, Oils, waxes
•Contain even more energy than carbs
•Cells contain lipids for long-term energy
•Main ingredient of cell membranes
ProteinsMeat, eggs, fish, nuts, beans
Structure:
◦ Made up of chains of Amino Acids- the building blocks of proteins
◦ 20 kinds of AA can combine in different combinations
Function:
◦ Make up organelles
◦ Make enzymes- speed up chemical reactions
◦ EX: Saliva breaks down carbohydrates to sugars in the mouth
Nucleic AcidsContain instructions that cells need to do jobs
Two types:
◦ DNA
◦ Genetic material that carries info about organism
◦ Passes on info to offspring
◦ Found in chromatin in nucleus
◦ RNA
◦ Used for Protein production
◦ Found in cytoplasm and in nucleus
Section 2: The Cell in its Environment
Selectively Permeable
◦ Ability of some substances to pass through the membrane while others cannot
◦ Let in oxygen and food molecules
◦ Move out waste materials
Three methods for material movement
◦ Diffusion
◦ Osmosis
◦ Active Transport
Passive
transport
1. Transport Proteins
2. Transport by Engulfing
Diffusion
•Main method of small molecule movement across cell membrane
•Move from area of high to low concentration
•Collisions cause molecules to spread out
•Passive transport- NO energy required;
meaning NO ATP from the mitochondria is needed
Osmosis Diffusion of water through cell membrane
Passive transport- NO energy required
Active TransportMovement of materials using cellular energy (ATP)
1. Transport Proteins “pick up” molecules and carry them in and out of cell
2. Transport by Engulfing
◦ Cell membrane surrounds a particle and brings it in
Section 3: PhotosynthesisProcess by which cells capture energy from sun and uses it to make food
Autotrophs like plants use photosynthesis
6 CO2 + 6 H2O C6H12O6 + 6 O2◦ Carbon dioxide + Water Glucose + Oxygen
◦ = requires light energy
2 stages1. Capturing the sun’s energy
2. Using energy to make food
Stage 1: Capturing the Sun’s Energy
Mostly occurs in the chloroplasts in leaves
Pigment- makes leaves green ◦ Responsible for absorbing light
◦ Chlorophyll- main pigment in photosynthesis
Uses captured light as energy for 2nd stage
Stage 2: Using Energy to make food
Cell uses captured energy to make sugars
Needs H2O (via roots) and CO2 (via stomata)
Materials move to chloroplasts
Chemical reactions result in glucose and oxygen production
Glucose is used by plant for energy
Oxygen is released back out into atmosphere
Section 4: RespirationRespiration
◦ Process by which cells obtain energy from glucose
◦ Aka. Cellular Respiration
◦ Must use respiration (or breathing in O2) to occur
Two Stages
1st stage- occurs in cytoplasm
◦ Molecules of glucose broken down into smaller molecules
2nd stage- occurs in mitochondria
◦ Small molecules broken down into even smaller molecules
◦ Oxygen needed and LOTS of ENERGY released
Respiration EquationC6H12O6 + 6 O2 6 CO2 + 6 H2O + ENERGY
*Photosynthesis and Respiration are a CYCLE
FermentationEnergy-releasing process that does not require oxygen
Two types:◦ Alcoholic fermentation (yeasts)
◦ Lactic Acid Fermentation (painful muscles)
Section 5: Cell Division
THREE STAGES
◦ Interphase
◦ Mitosis
◦ Cytokinesis
Stage 1: InterphasePeriod before cell division
Longest phase of cell cycle
3 steps◦ Cell grows
◦ Replication
◦ Cell makes a copy of its DNA
◦ Prepares to divide into 2 cells
Stage 2: Mitosis
Mitosis = Division of the Nucleus◦ ONE copy of the DNA is distributed
into each of the two daughter cells
1. Chromatin condenses into chromosomes
2. Cell stretches out
3. New structures moves to ends of cell
Stage 3: Cytokinesis
Cytoplasm divides
Parent cell becomes two daughter cells
In animal cells:
◦ Cell membrane squeezes around middle and cytoplasm pinches into two cells
In plant cells:
◦ Cell wall cannot squeeze together so a cell plate forms in the middle and splits cell into 2 new cells