Unit 2: Plants as a Fuel Source Study Guide PDF

Unit 2: Plants as a Fuel Source for the Body Study Guide Metabolism and Enzymes 1. Describe how energy flows from the sun to plants to animals and how energy is transformed from one form to another Plants absorb sunlight, make sugars and release oxygen; animals eat the plants and get...

Unit 2: Plants as a Fuel Source for the Body Study Guide Metabolism and Enzymes 1. Describe how energy flows from the sun to plants to animals and how energy is transformed from one form to another Plants absorb sunlight, make sugars and release oxygen; animals eat the plants and get energy from them 2. Define the following terms and understand how they are related to each other in the context of chemical reactions: - Catabolism- the process of enzymes breaking down large molecules into smaller pieces - Anabolism- the process of enzymes building large molecules - Exergonic- release energy into the environment when they occur; tend to be catabolic - Endergonic- require an input of energy to happen and store energy; tend to be anabolic 3. Explain how ATP releases energy and powers other reactions in a cell. Energy released in a an exergonic reaction is used to power other endergonic reactions in the cell by forming high energy bonds with a new molecule 4. Explain what an enzyme is, what it does, and how it works - Enzyme- type of protein that speeds up chemical reaction; they bring a substrate to its active site that makes it easier to break or form new bonds 5. Explain how temperature, pH, and interactions with other molecules affect enzyme activity - Temperature- affects the movement of the substrates and enzyme - pH- affects an enzyme’s shape and reactivity Plants as a Fuel Source: Plant Structure and Function 1. Describe the overall structure of an angiosperm (flowers, roots, shoots, and leaves) and how each component functions - Flowers- distinguishing characteristics of plants classified as angiosperms; the organ of sexual reproduction; fruits come from flowers - Roots- absorb water soil nutrients; anchor plant to the soil; absorb ions and water from soil; conduct water and ions to the shoot system; obtain energy from the sugar in the shoot system; store material produced in the shoot system for later use ➔ Adventitious roots- grow from shoot system; in ivy, adventitious anchor roots act to anchor the plant; prop roots of corn brace the plant  ➔ Pneumatophore roots- specialized lateral roots that function in gas exchange; oxygen in atmosphere can diffuse into root system through pneumatophores ➔ Storage roots- storage for Carbohydrates - Shoots- harvests light and carbon dioxide from atmosphere to produce sugars It also transports water to tissues above ground; absorb light; contains one or more stems and leaves; primary function is to protect the plant ➔ Stems- Vertical aboveground structures; consist of nodes where leaves are attached, and internodes-segments between nodes ➔ Herbaceous stems- Exhibit only vertical (primary) growth; no bark; found in herbs, most standard flowering plants; outermost surface is covered in a cuticle ➔ Woody stems- Exhibits both vertical and outward (secondary) growth which forms bark; found in trees, bushes and shrubs ➔ Leaves- large surface area; photosynthesis occurs here 1. Sepals enclose and protect a flower bud. 2. Petals: colorful and fragrant, advertising the flower to pollinators. 3. Stamens consist of a filament tipped by an anther, which contains sacs where pollen is produced. 4. Carpels: long slender style with a sticky stigma at its tip. Understand the importance of surface area to absorption of light, water, and nutrients Plants that are most efficient absorbers have a large surface area compared to its volume; absorbing photons; increase water uptake 2. Describe the nutrient requirements of plants and how soil can be modified to support plant growth Essential elements: a plant must obtain to complete its life cycle of growth and have reproductive success; to survive and grow, a plant must obtain water, carbon dioxide, and inorganic molecules ➔ Macronutrients- plants require in relatively large amounts (98% of the plant’s weight); carbon (C), hydrogen (H), oxygen (O), nitrogen (N), sulfur (S), phosphorus (P), potassium, calcium, magnesium ➔ Micronutrients- plants require in tiny quantities (0.3% of the plant’s weight); Chlorine, iron, manganese, boron, zinc, copper, nickel, molybdenum 3. Describe how ions, nutrients, and water enter the plant through the roots and move through the xylem Xylem- conducts water and dissolved nutrients from the root system to the shoot system  Transpiration - Water molecules diffuse out of stomata. This evaporation, called transpiration, creates tension on the chain of water molecules that run from the roots to the leaves;The tension pulls the chain of water molecules upward through the xylem cells. Water molecules cling to the cells by adhesion and stick to each other by cohesion; The tension created by transpiration pulls water and minerals upward from the soil into the xylem cells of the roots. 4. Describe the movement of sugars through the phloem after being produced via photosynthesis in a source cell Phloem- conducts sugars, amino acids, hormones, and other substances from roots to shoots and from shoots to roots; transports the products of photosynthesis from where they are made to where they are needed; translocation: the movement of sugars through plant by bulk flow from “sources” to “sinks” through the phloem Source- tissue where sugar enters the phloem; high sugar concentration Sink - a tissue where sugar exits the phloem; low sugar concentration Photosynthesis 1. Explain the relationship between autotrophs and heterotrophs - Autotrophs - make their own food from ions, molecules, and energy - Heterotrophs- obtain sugars from other organisms Their relationship: autotrophs send out sugars and oxygen that the heterotrophs obtain 2. Describe the anatomy and components of the chloroplasts (including the types of pigments that are located there) - 40-50 chloroplasts in a leaf - Double membraned- inner membrane, outer membrane - Stroma- fluid filled space where sugars will be made in the last step of photosynthesis - thylakoids stacked= grana in the stroma 3. Describe the process of photosynthesis Photosynthesis= CO2 + H2O -> C6H12O6 + 6O2 1. Light reactions use water and light to produce oxygen and chemical energy (ATP/NADPH) 2. Calvin cycle reactions use carbon dioxide and energy from the light reactions to produce sugar Explain the role of photosynthetic pigments in harnessing solar energy in the light reactions 1. Chlorophylls- absorb red and blue light; reflect and transmit green light  2. Carotenoids- absorb blue and green light; reflect and transmit yellow, orange and red light Explain how ATP and NADPH are produced in the light reactions - ATP synthase- protein that allows the facilitated diffusion of H+ across the thylakoid membrane; As H+ moves through the ATP synthase; As H+ moves through the ATP synthase, it spins and makes ATP from used up ADP and loose phosphates in the stroma of the chloroplast. Describe the role of the Calvin cycle 1. carbon fixation- involves adding of carbon atoms from CO2 to a starting molecule called RuBP; process converts, “fixes”, CO2 gas to biologically useful form; requires the enzyme Rubisco to facilitate the chemical reaction between CO2 and RuBP to make a new intermediate molecule 2. Production and release of a G3P molecule 3. regeneration of the starting molecule (RuBP) 4. Understand the global importance of photosynthesis - providing food and O2 for almost all living organisms. - Plants make much more food than they need. They store the excess in roots, tubers, seeds, fruits - About 50% of the carbohydrates made by photosynthesis is consumed as fuel for cellular respiration in the mitochondria of plant cells. - Sugars also serve as the starting material for making other organic molecules, such as proteins, lipids, and cellulose. - Many glucose molecules are linked together to make cellulose, the main component of cell walls. Nutrition and Digestion 1. Describe types of diets and feeding modes Diets: - Herbivores- eat plants - Carnivores- eat other animals - Omnivores- eat plants and animals Feeding modes: 1. Suspension feeders- filter small organisms from water by means of cilia- mucus lined nets 2. Deposit feeders- swallow organic- rich sediments and other types of deposited materials 3. Fluid feeders- suck or lap up blood, nectar, or other fluids 4. Mass feeders- seize and manipulate chunks of food 2. Describe the difference between the incomplete and complete digestive tracts The incomplete digestive tract has one opening for both ingestion and elimination that leads directly to the gastrovascular cavity whereas the complete digestive tract has two designated openings for ingestion and elimination 3. Describe the process that food takes from the mouth to the anus while explaining the role of each major organ ➔ Mouth: food is chewed; enzymes in saliva begin chemical breakdown of carbs and lipids - Salivary glands secrete amylase mucus- cleaves - Cells in the tongue synthesize and secrete lingual lipase, which begins the digestion of lipids. ➔ Esophagus- connects the mouth and stomach - Peristalsis- The food is propelled down the esophagus by a wave of muscle contractions ➔ Stomach- a tough, muscular pouch bracketed on both ends by ringlike muscles called sphincters-control the passage of material - When food enters the stomach, muscular contractions result in churning that mixes and breaks down the food mechanically while enzymes digest proteins and lipids - Parietal cells secrete HCl when stimulated by the hormone gastrin - Pepsin - digests protein - Mucous cells- secrete mucus, which lines the gastric epithelium ➔ Small intestine- A long tube folded into a compact space in the abdomen; master organ for chemical digestion and absorption of nutrients into the bloodstream - Food mixes with secretions from the pancreas, liver, and gallbladder and begins to move through the tube - As food is digested in the small intestine, nutrients are absorbed across the epithelia of the small intestine. 4. Know the functions of digestive enzymes--what they digest and where that digestion takes place. - Pancreatic enzymes- digest proteins are stored in an inactive form in the pancreas - Enteropeptidase (in the SI) cuts a pancreatic enzyme called trypsinogen (from pancreas), resulting in the active enzyme trypsin- happens in small intestine - Trypsin- activates other enzymes that were synthesized by the pancreas and secreted in an inactive form; happens in small intestine - Pancreatic juice contains  bicarbonate ions into the small intestine to neutralize stomach acid. Pancreatic Enzymes that digest protein, lipids, and carbs Pancreatic lipase- completes digestion of lipids 5. Discuss the roles of transport and osmosis during the absorption process of nutrients and water Nutrients pass into epithelial cells by diffusion against concentration gradients. Fatty acids and glycerol are absorbed by intestinal cells, recombined into fats, coated with proteins, transported into lymph vessels Amino acids and sugars pass across the thin walls of the capillaries into blood, and go to the liver Nutrient Transport: Respiratory and Circulatory Systems 1. Explain the relationship between the digestive, respiratory, and circulatory systems With the respiratory system, we get oxygen, which is needed to perform cellular respiration ( break down sugars to produce ATP). We consume food and break it down via the digestive system to absorb nutrients. Those nutrients along with oxygen are then transported to cells throughout the body via the circulatory system. 2. Describe the structure and function of each component in the respiratory system ➔ Nasal cavity- air is inhaled into the nostril into the nasal cavity ➔ pharynx/ esophagus ➔ Larynx ➔ Trachea- carries inhaled air to narrow tubes called bronchi ➔ Bronchi- bronchi branch off into even narrower tubes called bronchioles ➔ Lungs- Internal organs used for gas exchange ➔ Alveoli- tiny sacs that greatly increase the surface area for gas exchange ➔ Diaphragm- separates the abdominal cavity from the thoracic cavity and helps ventilate the lungs ➔ Brain- houses breathing control center- keeps breathing in tune with body needs, sensing/ responding to the CO2 level in the blood 3. Explain the how negative pressure works to bring oxygen into the lungs Inhalation- diaphragm moves down and pressure in the chest cavity is lowered, causing lungs to expand and air to move in Exhalation- as diaphragm relaxes, chest cavity decreases and air is exhaled 4. Describe the structure and function of each component in the circulatory system (components of blood, heart, types of vessels)  ➔ Arteries- tough, thick walled vessels that take blood away from the heart under high pressure; oxygen rich; have a connective tissue layer with elastic fibers to allow for expansion when high pressure blood is pumped through ➔ Capillaries- one cell thick wall that allows gas exchange and other molecules between blood and tissues in networks called capillary beds; are everywhere, are extremely thin to facilitate diffusion, experience lowest pressure ➔ Veins- carries blood to the heart; oxygen poor; have relatively low pressure. The walls are thinner than arteries and the diameter is larger 5. Be able to narrate the path blood takes through the heart, pulmonary system, and systemic system. (It might help to diagram) ➔ Heart: simultaneously pumps oxygen poor blood to the lungs and oxygen rich blood to the body; contains two chambers Atrium ( atria)-) receives blood returning from circulation Ventricle- generates force to propel the blood out of the heart and through the circulatory system - Pathway: (right side) inferior vena cava→right atrium→tricuspid valve→right ventricle→pulmonary valve→pulmonary artery→lungs→(left side) pulmonary vein→left atrium→ bicuspid valve→ left ventricle→ aortic valve→ aorta ( carries oxygenated blood throughout the body) - Blood flow through the pulmonary circuit (between heart & lungs): CO2-rich blood from the body tissues enters the right atrium Then pumped into the right ventricle O2-poor blood leaves the heart through pulmonary arteries Goes through the lungs, exchanges CO2 for O2 Returns to the left atrium through the pulmonary veins into the left atrium Travels into the Systemic circuit - Blood flow through the systemic circuit (between heart & body) Left ventricle pumps O2-rich blood out through the aorta to capillaries of the upper and lower body tissues CO2-rich blood from the body tissues drains via the superior vena cava (from the head and arms) or inferior vena cava (from the lower trunk and legs) into the right atrium Then moves from the right ventricle to the lungs via the pulmonary arteries to exchange CO2 for O2 6. Describe the movement of oxygen and carbon dioxide between the lungs, blood, and body cells - Red blood cells (R B C s)— transport oxygen from lungs to body tissues and participate in transporting carbon dioxide from tissues to lungs RBCS- bags of hemoglobin used to transport oxygen (and CO2) Hemoglobin - contain iron that allows it to pick up oxygen and deliver it Herme- chemical group attached to the hemoglobin; iron atom at the center; each iron binds one O2 molecule