Controlled release of energy in the form of ATP from organic compounds in cells

(Last Step)Two pyruvate molecules are formed by removing two phosphate groups from each molecule. These phosphate groups are given to ADP molecules and form ATP. 

·      Glycolysis occurs in the cytoplasm of cells. Two ATP molecules are used and 4 ATP molecules are produced. Therefore there is a net yield of two ATP molecules. Also, two NAD⁺ are converted into NADH + H⁺ during glycolysis. 

 Electrons are given to proton pumps that are embedded in the membrane between the matrix and inner membrane/cristae of the mitochondrion. The pumps are reduced, giving them energy to pump protons into the inner membrane space. The electrons are transferred along a chain of pumps, continuously losing energy. The proton pumps create a high concentration gradient of protons (H+)inside the inner membrane space. Thus, protons diffuse back into the matrix through facilitated diffusion of ATP synthase (channel protein and enzyme). As the protons pass along this protein channel, the kinetic energy of the protons causes the ATP synthase molecule to turn slightly, exposing active sites that create ATP by binding ADP with inorganic phosphate molecules. The result is 34 ATP produced by oxidative phosphorylation.

CO₂, NADH + H+, Acetyl CoA

Draw and label a diagram showing the structure of mitochondria as seen in electron micrographs

·      Watery substance that contains ribosomes and many enzymes. These enzymes are vital for the link reaction and the Krebs cycle. 

·      The electron transport chain and ATP synthase are found in this membrane. These are vital for oxidative phosphorylation. 

Happens in the stroma. Consists of Calvin Cycle (made up of 3 stages)

o      Carbonfixation: Carbon dioxide is incorporated in a 5C molecule ribulose biphosphate (RuBP), catalyzed by an enzyme called rubisco, a 6C moleculeis formed which is very unstable and splits into two molecules of 3 carbons each.

o      Reduction: Molecule 3C is going to add a P group and H from (NADPH) and form G3P

o      Regeneration of RuBP: G3P is rearranged to form RuBP

o      The stage of photosynthesis that occurs in the thylakoid membranes. Converts solar energy to the chemical energy of ATP and NADPH

o      Rate of photosynthesis increases as light intensity increases;

o      Photosynthetic rate reaches plateau at high light levels;

o      Photosynthetic rate rises as CO₂ concentration rises;

o      Up to a maximum when rate levels off;

o      Rate of photosynthesis increases with increase in temperature;

o      Up to optimal level / maximum;

High temperatures reduce the rate of photosynthesis 

Draw and label the structure of a chloroplast as seen in electron micrographs

Explain the relationship between the structure of the chloroplast and its function

·      The stroma - Contains many enzymes, including rubisco, which are important for the reactions of the Calvin cycle.

·      The thylakoids - Have a large surface area for light absorption and the space within them allows rapid accumulation of protons.

·      The visible light spectrum (400-700 nanometers) is used by plants in photosynthesis. If a plant is green, then it reflects green wavelengths of light and absorbs red, orange, some yellow, blue, indigo, and violet wavelengths of light. This means that the absorption spectrum of photosynthetic pigments in green plants is high for low and high wave lengths of light, but not for middle wave lengths of light (green), which are reflected by the photosynthetic pigments and are not absorbed.

·      a system made up of organisms as well as the abiotic factors in the area.

·      a group of organisms of the same species who live in the same area at the same time

·      the environment in which a species normally lives or the location of a living organism

·      also known as producers, they can make their own food - main producers are photosynthesizers, which utilize the sun's energy and convert it into chemical energy, which they use to build their bodies. Considered net producers of O2.

·      an organism that ingests other organic matter that is living or recently killed.

 Describe what is meant by a food chain, giving three examples, each with at least three linkages (four organisms):

A food chain shows the direction of energy flow from one species to another. For example, an arrow from A to B means that A is being eaten by B and therefore indicates the direction of the energy flow. 

Ex: 1)Mosquito larva --->beetle --->mouse--->snake

          2)Plankton---->krill---->mullet--->shark

          3)Earwig---->lizard--->shrew-->owl

Construct a food web containing up to 10 organisms using appropriate information

State that light is the initial energy source for almost all communities

• Energy flows from producers to primary consumers, to secondary consumers, to tertiary consumers 
• Energy is lost between trophic levels in the form of heat through cell respiration, faeces, tissue loss and death 
• Some of this lost energy is used by detritivores and saprotrophs. These in turn also lose energy in the form of heat through cell respiration  

• The model shows the typical loss of energy from solar radiation through the various trophic levels
• The volume of one layer is 10% of the layer below
• It is this loss of energy which makes food chains relatively short
• In extreme environments like the arctic, the initial trapping of energy by producers is low, thus the food chains are short
• In a tropical rainforest, the trapping of energy is more efficient and therefore food chains are longer, webs are more complex

• Energy is not recycled; it is constantly supplied to the ecosystem through light energy
• Energy is lost from the ecosystem in the form of heat through cell respiration
• Nutrients must be recycled as there is only a limited supply of them
• They are absorbed by the environment, used by organisms and then returned to the environment

• The incoming radiation from the sun is short wave ultraviolet and visible radiation
• Some of this radiation is absorbed by the earths atmosphere
• The radiation which is reflected back into space is infrared radiation and has a longer wavelength
• The greenhouse gases in the atmosphere absorb some of this infrared radiation and re-reflect it back towards the earth
• This causes the green house effect and results in an increase in average mean temperatures on earth
• A rise in greenhouse gases results in an increase of the green house effect which can be disastrous for the planet

• The arctic ice cap may disappear as glaciers start to melt and break up into icebergs
• Permafrost will melt during the summer season which will increase the rate of decomposition of trapped organic matter, including peat and detritus. This in turn will increase the release of carbon dioxide which will increase the green house effect even further
• Species adapted to temperature conditions will migrate north which will alter food chains and have consequences on the animals in the higher trophic levels
• Marine species in the arctic water may become extinct as these are very sensitive to temperature changes within the sea water
• Polar bears may face extinction as they loose their ice habitat and therefore can no longer feed or breed as they normally would
• Pests and diseases may become quite common with rises in temperature
• As the ice melts, sea levels will rise and flood low lying areas of land
• Extreme weather events such as storms might become common and have disastrous effects on certain species

• Natality: increases population size as offspring are added to the population
• Immigration: increases population size as individuals have moved into the area from somewhere else and so this adds to the population
• Mortality: decreases the population as some individuals get eaten, die or old age or get sick
• Emigration: decreases the population as individuals have moved out of the area to go live somewhere else

• Rapid increase in population growth 
• Natality rate exceeds mortality rate 
• Abundant resources available. (food, water, shelter) 
• Diseases and predators are rare 

• Natality rate starts to fall and/or mortality rate starts to rise 
• There is a decrease in the number of resources 
• An increase in the number of predators and diseases 
• Population still increasing but at a slower rate 

• No more population growth, population size is constant 
• Natality rate is equal to mortality rate 
• The population has reached the carrying capacity of the environment 
• The limited resources and the common predators and diseases keep the population numbers constant 

Outline the binomial system of nomenclature 

• Called binomial because two names are used
• First name is genus, with the first name being a capital
• Second name is species, with no capital
• Italics are used when the name is printed
• The name is underlined if it is handwritten

• Kingdom: Animalia/Plantae
• Phylum: Chordata/Coniferophyta
• Class: Mammalia/Pinopsida
• Order: Cetacea/Pinales
• Family: Baleanoptera/Sequoi
• Species: Musculus/Semperivirens

bryophyta: mosses

no roots, only structures called rhizoids, which resemble root hairs

no true leaves or stems, both lacking vascular tissue

maximum height = 0.5 m

reproductive structures: spores produced in capsules at the end of stalks

have true roots, leaves and non-woody stems, all containing vascular tissue

maximum height = 15 m

reproductive structures: spores produced in sporangia, usually on the underside of leaves

have roots, leaves and wood stems all containing vascular tissue

maximum height = 100 m

reproductive structures:

-male cones produce pollen

-female cones produce ovules on the underside of scales

-seeds develop from fertilized eggs with in ovules 

angiospermophyta: flowering plants

have roots, leaves and stems all containing vascular tissue

maximum height = 100 m

reproductive structures:

-flowers, containing female pistil and/or male stamen

-male stamens produce pollen

-female pistils produce ovaries containing eggs

-seeds develop from fertilized eggs with in ovule

-fruits develop from ovaries to disperse seeds

no clear symmetry

attached to a surface

pores through body

no mouth or anus 

radial symmetry

tentacles

stinging cells

mouth, but no anus 

bilateral symmetry

unsegmented, flat body

mouth, but no anus 

bilateral symmetry

segmented

mouth and anus 

 mollusca: slugs, snail, clams, squids

muscular foot and mantle

shell usually present

segmentation not visible

mouth and anus 

bilateral symmetry

exoskeleton

segmentation

jointed appendages 

• Scotch broom was introduced to British Columbia as a garden plant. It has up to 18 000 seeds per plant, can survive drought, and fixes nitrogen in the soil, causing conditions that many native species have trouble growing in. Together with other introduced species, it is competing with the keystone species Garry oak on Vancouver Island 
• European starlings outcompete native birds for nesting sites, and cause decreases in their populations. Barn owls are able to keep the numbers of starlings low in some areas 
• Eurasian milfoil forms mats on the surface of waterways that decrease the amount of sunlight available to organisms lower down. It is spread by boat traffic since it can regrow from small pieces   

• The foods that we eat are not necessarily usable in their current form by our tissues. They have to be broken down and changed into another form    
• Food molecules are simply too large to be absorbed by the villi in the small intenstine, once again they have to be broken down into small forms 

• Enzymes break down large food molecules into smaller ones. 
• Speed up the process of digestion by lowering the activation energy for the reaction 
• Work at body temperature   

State the source, substrate, products and optimum pH conditions for one amylase, one protease and one lipase

Describe the function of the stomach

Absorption is when food molecules pass through a layer of cells such as passing through the villi 

Assimilation is when food actually becomes part of the body's tissue 

• It increases the surface area of the small intestine 
• The epithelium has a surface of only a thin layer of cells 
• Protein channels in the microvilli allow for quick absorption of foods via facilitated diffusion and active transport 
• Blood capillaries close to epithelium making it only a small distance for diffusion to occur   

Draw and label a diagram of the heart showing the four chambers, associated blood vessels, valves and the route of blood through the heart:

State that the coronary arteries supply heart muscle with oxygen and nutrients

• The heart has its own blood vessels 
• Blood passing through the chambers of the heart does not provide nutrient or oxygen to the heart muscle cells 
• Coronary arteries are branches of the aorta which provide the heart muscle with a supply of oxygen and nutrient 
• The coronary arteries branch and spread through the heart muscle supplying the individual muscles cells   

• The right atrium relaxes for the blood to be received from the superior and inferior vena cava 
• The atrioventricular valve opens for blood to go to the right ventricle by the contracting atrium 
• The right ventricle then relaxes to receive the blood from the atrium. Then it contracts in order to open up the pulmonary valves. Deoxygenated blood goes through to the pulmonary artery, where it enters the lungs so that the blood will be oxygenated 
• Blood returns from the lungs to the heart through the pulmonary veins, now oxygenated 
• The left atrium relaxes to receive it and then contracts to pump blood and open the atrioventricular valve where then the blood goes to the relaxed left ventricle 
• The left ventricle contracts to open the semilunar valves and then the blood goes through the aorta to the rest of the body   

Describe the control of the heartbeat in terms of myogenic muscle contraction, the role of the pacemaker, nerves, the medulla of the brain and epinephrine

• Heart muscle can contract by itself (myogenic muscle contraction)
• Pacemaker initiates contractions 
• One nerve carries messages from the brain to the pacemaker to speed up the beating of the heart 
• One nerve carries messages from the brain to the pacemaker to slow down the beating of the heart 
• Adrenaline signals the pacemaker to increase the beating of the heart 
  

• Thick outer layer of longitudinal collagen and elastic fibres prevents leaks and bulges 
• Thick wall withstands high pressure 
• Layers of circular elastic fibres and muscle fibres to pump blood 
• Narrow lumen to maintain high pressure   

• Wall is one cell layer thick so distance for diffusion is small 
• Pores allow plasma to leak out and form tissue fluid. Phagocytes can also pass through pores 
• Very narrow lumen so that many can fit in a small space   

• Thin layer with few circular elastic fibres and muscle fibres as blood does not flow in pulses 
• Thin walls so that nearby muscles can help push blood towards the heart 
• Thin outer layer of longitudinal collagen and elastic fibers as pressure is low 
• Wide lumen to accomodate the slow flowing blood   

• To maintain the concentration gradients of oxygen and carbon dioxide in the alveoli 
• The body needs oxygen to make ATP via cell respiration 
• The body needs to get rid of carbon dioxide, which is a product of cell respiration 
• Oxygen needs to diffuse from the alveoli into the blood. Carbon dioxide needs to diffuse from the blood into the alveoli 
• To do so there must be a high oxygen concentration and a low carbon dioxide concentration in the alveoli 
• A ventilation system makes this possible by getting rid of the carbon dioxide in the alveoli and bringing in more oxygen   

Describe the features of alveoli that adapt them to gas exchange

• Great numbers increase the surface area for gas exchange 
• Wall made up of single layer of cells and so are the walls of the capillaries so diffusion distance is small allowing rapid gas exchange 
• Covered by a dense network of capillaries, which have low oxygen and high carbon dioxide concentrations. This allows oxygen to diffuse into the blood and carbon dioxide to diffuse out of the blood 
• Some cells in the walls secret fluid allowing gases to dissolve. Fluid also prevents the sides of alveoli from sticking together   

Draw and label a diagram of the ventilation system, including trachea, lungs bronchi, bronchioles, and alveoli

Inhalation

• external intercostal muscles contract; moves the ribcage up and out 
• diaphragm contracts.and moves down becoming relatively flat 
• Both muscle contractions result in an increase in volume of thorax resulting in a drop in pressure inside the thorax 
• Pressure eventually drops below atmospheric pressure 
• Air then flow into the lungs from outside the body, through the mouth or nose, trachea, bronchi and bronchioles 
• Air continues to enter the lungs until the pressure inside the lungs rises to the atmospheric pressure   

• internal intercostal muscles contract; moves the ribcage down and in 
• abdominal muscles contract; pushes the diaphragm up, back into a dome shape 
• Both muscle contractions result in  decrease in volume of thorax 
• decrease in volume = increase in pressure inside thorax 
• Eventually the pressure rises above atmospheric pressure. 
• Air then flows out of the lungs to outside of the body through the nose or mouth 
• Air continues to flow out of the lungs until the pressure in the lungs has fallen back to atmospheric pressure