Maintaining A Balance

Front 1

Identifythe role of enzymes in metabolism, describe their chemical composition and usea simple model to describe their specifity on substrates.

Back 1

Metabolism are all of the chemical reactions that take place in an organism. Enzymes are proteins, which are made up from the polymerisation of amino acids. Enzymes maintain an organism’s metabolism. They speed up the rate of reaction. § They are reusable. § Only small amounts needed § Made by cell, controlled by nucleus. § Highly Specific – particular substrate for each enzyme. Lock and key model: Enzyme can only react with specific substrate. Like a key in a lock. Doesn’t change shape. Induced Fit Model: Enzyme adapts shape to fit substrate. § After reaction it returns to original shape.

Front 2

Identifythe pH as a way of describing the acidity of a substance.b8=%

Back 2

pH shows how much hydrogen ion concentration in substance. Acidic (1-7) : large amount of hydrogen Neutral (7) Alkalinity (7-14) : very little hydrogen-

Front 3

pH shows how much hydrogen ion concentration in substance. Acidic (1-7) : large amount of hydrogen Neutral (7) Alkalinity (7-14) : very little hydrogen-

Back 3

§ Explain why the maintenance of a constant internal environment is important for optimal metabolic efficiency. Factors that affect enzymes activity and therefore metabolism: · Temperature – As temperature increases, rate of reaction increases until optimum temperature when the enzyme is then denatured. · PH- As pH levels increase, rate of reaction increases until 7. The enzyme is then denatured. · Substrate concentration- As substrate concentration increases so does the rate of reaction, until it reaches saturation point at which rate of reaction levels off. Denatured – peptides bonds break, which makes active site inactive, therefore destroying enzyme if those three are not at optimum point. i

Front 4

Describehomeostasis as the process by which organisms maintain a relatively stableinternal environment. 88%

Back 4

No matter what is happening in the external environment, the body is capable of maintaining a constant internal environment. Homeostasis – constant internal composition of a cell or organism and the mechanisms that maintain it. Blood sugar : 90mg Temp: 37degrees pH: 7.38

Front 5

§ Explain that homeostasis consists of two stages: § Detecting the change Counteracting changes from the stable state.& wi8r

Back 5

Homeostatic system has three parts: Receptor, Control centre, Effector. Feedback process Receptor: detect changes within internal/external environment. (stimuli) Control Centre: decide whether or not a response should take place. Effector: Carries out response.

Front 6

Outlinethe role of the nervous system in detecting and responding to environmentalchanges.><89%

Back 6

Nervous system contains two parts: § Central nervous System – receives information, interprets and initiates response. § Peripheral Nervous System – system of nerves around the body which connect to the receptors and effectors. It sends the message. The Endocrine system also plays a role: It secretes certain hormones in response to certain stimuli. Eg. Thermoreceptors detect heat. Sweating isproduced and dilated blood vessels in order to lode heat. :

Front 7

Identifythe broad range of temperatures over which life is found compared with thenarrow limits for individual species.

Back 7

100degrees to -70degrees on Earth. Organisms have different optimal temperatures. When they are out of optimal temperature theyrisk death. Terrestrial animals between 0-45degrees. Any higher or lowerenzymes could be denatured.

Front 8

Identifysome responses of plants to temperature change. ]:2

Back 8

Responses to heat: § Leaves hang down and are small to decrease SA, means decrease water loss and solar radiation. § Close stomata’s in order to stop transpiration. Responses to cold: § Dormancy Organic antifreezempeR9

Front 9

§ Identify the form(s) in which each of the following is carried inblood:vel-n;ޖC

Back 9

§ CO2 – Dissolved in plasma. Bind to haemoglobin.(carbaminohaemoglobin)§ O2 – Is carried by haemoglobin in red blood cells.§ H2O – Dissolved in blood plasma.§ Salt - Dissolved in blood plasma.§ Lipids – Carried in a package called a chylomicron.§ Nitrogenous Waste – Such as urea, uric acid and creatinine isdissolved in blood plasma.Other products of digestion - Dissolved in bloodplasma.and [:Ј

Front 10

Explainthe adaptive advantage of haemoglobinmso-ad>#3

Back 10

Haemoglobin – Red pigment in red bloodcells. (280 million haemoglobin in each red blood cell)The adaptive advantage is:· Haemoglobin transports oxygenfrom lungs to body cells. This allows organism to carry out metabolicfunctions. · Haemoglobin carries some Carbondioxide from body cells to lungs. This allows organism to maintain pH level asexcess CO2 in blood can alter blood pH.· A large proportion of oxygencan be carried within the organism allowing it to function at optimum level.Haemoglobin allows four water molecules to bind withthe iron ions within the haemoglobin structure. (this is useful as oxygen isnot soluble in water and does not dissolve in blood plasma) oxyhaemoglobin. >

Front 11

Comparethe structure of arteries, capillaries and veins in relation to their function. 8@

Back 11

Blood Vessel Structure/Function Arteries · Three layers: Outer connetive tissue, layer of muscle then inner endothelial layer. · The muscle is thick as it needs to transport blood under high pressure. Artery can stretch. Artery away. Veins · Three layers same. · Low pressure therefore smaller muscle. · To prevent backflow of blood veins have VALVES. Capillaries · Thin structure to allow transport of substances between blood and cells. · The lumen (hole) is small allowing only one blood cell at a time.

Front 12

Describethe main changes in the chemical composition of the blood as it moves aroundthe body and identify tissues in which these changes occur.s8'

Back 12

Pulmonary system – · Blood flows from the heart tothe lungs then back to the heart. · Fast rate, low pressure.· The blood has returned from thebody therefore high CO2.· The CO2 is then released fromblood into lungs. Then is breathed out.· Oxygen goes from alveoli intoblood cells. Then goes to heart.Carbondioxide levels decrease, oxygen levels increase. Systematic system-· Pumps oxygenated blood to therest of body (not lungs).· CO2 is picked up. Urea ispicked up and transported to kidneys form liver. · Digestion products transportedto liver.· Deoxygenated blood returns toheart.Oxygenlevels decrease, carbon dioxide, urea and products of digestion levels increase38޺

Front 13

Outlinethe need for oxygen in living cells and explain why removal of carbon dioxidefrom cells is necessary.

Back 13

§ Need oxygen for cellular respiration. Respiration is the process bywhich glucose is broken down using oxygen to produce ATP. Glucose + oxygen = cO2 +water + ATP§ Oxygen is supplied via haemoglobin.§ The by-product of this reaction is CO2. CO2 is no longer required inthe body and therefore must be removed. It is removed in three ways: Dissolvedin plasma, attached to haemoglobin or as hydrogen carbonate ions in plasma. § The blood then carries the CO2 to the lungs, where it is breathedout.If CO2 is not removed it can effect pH levels,which can mean that the ability of haemoglobin to bind to oxygen decreases,therefore not allowing cellular respiration to occur. "08f

Front 14

Describecurrent theories about processes responsible for the movement of materialsthrough plants in xylem and phloem tissue. < 8%

Back 14

Transpiration (xylem) – loss of waterthrough the leaves. The water moves up through the xylem from the roots. Thewater moves up the xylem due to concentration gradient and root pressurepushing it up. Translocation (phloem) – movement of sugarsin phloem in any direction. From the sugar source to the sugar sink. Sugar is loaded into phloem from cells by activetransport. This increases solute concentration in phloem meaning water moves inby osmosis. Due to water pressure differences the water flows form highpressure to low pressure carrying solute etc. Pressure flow drives the sugars from areas of high conc. (source) tolow cons. (sink).

Front 15

Analyseinformation from secondary sources to identify current technologies that allowmeasurement of oxygen saturation and carbon dioxide concentrations in blood anddescribe and explain the conditions under which these technologies are used.or-lat8"*

Back 15

Blood Gas Analyser-§ Invasive.§ Takes small samples of blood and analyses the oxygen using twoelectrodes.§ The oxygen diffuses through a membrane between the two electrodes,which produces a small current. The size of current shows how much oxygen.§ CO2 level are measured placing blood in one chamber and hydrogenelectrode in the other. CO2 diffuses into hydrogen ion chamber. Then pH ismeasured. § Used in intensive care units. Light changes in CO2 levels and pooroxygen saturation can be bad for children. Pulse Oximeter-§ Non-invasive.§ Device is attached to finger and measures oxygen saturation withhaemoglobin and pulse rate. A light source passes through the blood and theprocessor calculates how much light is absorbed depending on the degree of oxygensaturation to the haemoglobin.§ Used in hospitals.Monitors oxygen, pulse and blood flow levels.

Front 16

Analyseinformation from secondary sources to identify the products extracted fromdonated blood and discuss the uses of these products.PY8$]

Back 16

Blood Product Use Whole blood Replace large amounts of blood. Red blood cells Given for suffering anaemia. (iron deficiency) White blood cells Patients with low white blood cell count or in cases of bacterial infection. plasma Patients after trauma or surgery. Platelets Patients suffering haemorrhaging or bleeding due to diseases (leukaemia). http8y-

Front 17

Explainwhy the concentration of water in cells should be maintained within a narrowrange for optimal function.H:;-

Back 17

Conc. Of water must stay within a narrowrange because:§ Its an excellent solvent. Too much or not enough water can lead toslower reactions.§ For larger molecules (proteins), water acts as a hydrating layer toprevent the protein from breaking down. (colloid)§ Too much water can cause cells to swell (hypotonic) and burst. Toolittle water causes the cell to shrivel (hypertonic). Isotonic is perfect.§ Water is lubricating therefore the perfect conc. Of water allows theproduction of mucus.§ Water is needed in metabolism.§ Water is the major transporter of nutrients around body.§ Water maintains body temp.Water cushions the body.

Front 18

Explainwhy the removal of wastes is essential for continued metabolic activity. v

Back 18

Wastes affect enzyme activity Optimum enzyme activity not reached. Enzymes not catalysing reactions. Disrupts metabolism. Damage to cellular components Organelles damaged = no longer function/ incorrect responses/cell death Excess Hydrogen ions Makes surrounding ions more acidic = affects reaction rate enzymes and saturation rate haemoglobin Excess ammonia, urea, toxins and drugs Brain associated problems

Front 19

Identifythe role of the kidney on the excretory system of fish and mammals. mso-:&?

Back 19

Fish - § OsmoregulationAdjust the level of water and mineral ions inorder to maintain balanced internal fluid within cells. Z:ў

Mammal - § OsmoregulationTo excrete urea and nitrogenous wastes.uB:ɖ

Front 20

Explainwhy the processes of diffusion and osmosis are inadequate in removing dissolvednitrogenous wastes on some organisms. <

Back 20

§ Diffusion and osmosis are slow. The removal of wastes is needed tobe done quickly. § Nitrogenous wastes are made up of large complex proteins. Thesemolecules need to be broken down into small products (urea). Once broken downthen Diffusion takes place in kidney as they are smaller.Nitrogenous wastes aren’t made of water andtherefore osmosis cannot occur. /

Front 21

Distinguishbetween active and passive transport and relate these to processes occurring inthe mammalian kidney.;:<޷;

Back 21

Filtration and reabsorption occur in tinyunits (nephrons). In these nephrons active and passive transport take place. <ޖ

Active - Movement of substance requires energy. Movement is against conc. gradient (low-high) Occurs in proximal tubule, the ascending loop of Henle and the distal tubule. Important nutrients are filtered and reabsorbed. i<V

Passive - Movement of substances doesn’t require energy. Goes from high-low. Occurs in proximal tubule, descending loop of Henle, ascending loop of Henle, distal tubule and collecting duct. It removes waste and reabsorbs nutrients. <X

Front 22

Explainhow the process of filtration and reabsorption in the mammalian nephron regulatebody fluid composition.:<޷;

Back 22

Filtration regulates body fluid by:§ Blood crosses from the glomerulus to the Bowmans capsule byfiltration.§ Blood pressure forces urea, amino acids, salts and water across.They become glomerular fluid.§ Blood cells and proteins are too large and filtered out.Filtration controls what molecules enterthe nephrons as well as regulate fluid composition. Reabsorption regulates body fluids by:§ Essential molecules in filtrate are reabsorbed in blood (prox anddist. Tubes) Like glucose, amino acids, salts and water.§ Toxins are absorbed from blood and secreted.Reabsorption maintains constant concentration ofessential molecules in blood stream. Without reabsorption large amounts ofthese molecules would leave the body, meaning that the body fluid would beunbalanced. Reabsorption reabsorbs nutrients from filtrate and secretes toxins.

Front 23

Outlinethe role of the hormones, aldosterone, and adh (anti-diuretic hormone) in theregulation of water and salt levels in blood.pt; f5<޸$

Back 23

Aldosterone –§ Hormone that controls glomerular blood pressure.§ Found in adrenal cortex above kidney.§ Function is to regulate salt levels in blood. It increasesreabsorption of sodium ions, to regulate their concentration. The sodium ionsthen enter blood at distal tubule. Water and sodium increase blood volume,therefore blood pressure. ADH – § Hormone that prevents water from being lost in urine.§ Function to make collecting ducts more permeable so that water canbe reabsorbed back into blood.§ Released by hypothalamus, when it detects low water levels.When too much water /or low solute concentrationwater needs to be excreted therefore less ADH released.v8

Front 24

Defineenantiostasis as the maintenance of metabolic and physiological function inresponse to variations in the environment and discuss its importance toestuarine organisms in maintaining appropriate salt concentrations. ntH<)

Back 24

Enantiostasis - the maintenance ofmetabolic and physiological function in response to variations in theenvironment. § Enantiostasis is important for estuarine organisms as it maintainsappropriate salt and water concentrations.§ Marine and freshwater fish – constantly maintaining salt/waterbalance. Marine fish drink large amounts and excrete small concentrated urine.Freshwater fish drink large amounts and exrete large amounts of dilute urine.They are osmoregulators.§ Osmoconformers maintain their internal fluids at the sameconcentration as ext. env.§ Tides means that salt/water concentration is always changing. Organisms are able to tolerate salt range inthese areas. Crabs and Sharks (osmoconformerse9:

Front 25

Describeadaptations of a range of terrestrial Australian plants that assist inminimising water loss. dow9<޴8

Back 25

Banksia – Woody fruit that are fireresistant. Not fleshy which enables it to reduce water loss. Baobab- Store large amounts of water intrunk. Eucalypt – Vertically hanging leaves. Reduceexposure to sun and reduce water loss.tPaj<

Front 26

Performa first-hand investigation of the structure of a mammalian kidney bydissection, use of model or visual resource and identify the regions involvedin the excretion of waste products.emeL<-

Back 26

Renal Medulla – Contains thousands offiltration units called nephrons.Renal Cortex –Outer protective layer.Calyces – Individualtubing that connects medullas.Ureter– Tube that collects urine and take it to bladder.t:-.25i;F

Front 27

Gather,process and analyse information from secondary sources to compare the processof renal dialysis with the function of the kidney.5<޸$

Back 27

Renal Dialysis – § Blood through tube. This tube is separated from the dialysis tubingby semi-permeable membrane.§ Tube contains molecules and ion essential for body. Wastes like ureapass through membrane into dialysis tube. No reabsorption.§ ONLY filtration occurs.§ 4-6 hours§ Wastes removed, dialysis fluid discarded and filtered blood returnsto body. Kidney –§ Permeable membrane in nephron. Essential molecules are transportedin or out of nephrons.§ Wastes pass through nephron to collecting duct then bladder.§ Filtration AND reabsorption occurs.§ Varies I time.Wasteis removed (urine). Filtered blood returns to body via renal vein. su=<ް<

Front 28

Presentinformation to outline the general use of hormone replacement therapy in peoplewho cannot secrete aldosterone. :{;<޶:

Back 28

§ People who cannot secrete aldosterone suffer from Addison’s disease.§ Addison’s disease is the inability of the adrenal cortex to secretesufficient amounts of aldosterone.§ They must increase salt intake. And take a mineralocorticoid knownas fludrocortisones once a day. If a patient has Addisonian crisis, the patienthas hydrocortisone injections, saline solution and dextrose. ng=Y9