Bioengenetics Flashcards
What is photosynthesis?
- Chemical endothermic reaction converting light energy
- To chemical energy in the form of glucose
- Providing the organism with energy
Word and Symbol equation for photosynthesis
Carbon Dioxide + Water –> Glucose + Oxygen
6CO2 + 6H2O –> C6H12O6 + 6O2
How does temperature affect the rate of Photosynthesis?
- Increasing temp catalyses rate of reaction, so it increases
- Optimal temperature is perfect
- If temperature exceeds optimal the enzyme becomes denatured
- So rate of reaction decreases
How does Light Intensity affect the rate of photosynthesis?
- AS light intensity increases
- Rate of photosynthesis increases too
How does CO2 affect the rate of Photosynthesis?
- As CO2 increases
- Rate of photosynthesis increases
What is a LIMITING FACTOR?
Something present in the environment in such short supply that it restricts other living processes from occurring
What are some examples of limiting factors for photosynthesis?
LIGHT, TEMPERATURE, CO2
What is the Inverse Square Law?
- If you double the distance from the light source to the plant
- The number of bubbles per minute falls by a factor of 4
Light intensity = 1 / d^2
How can the glucose from photosynthesis be used?
- Respiration
- Converted into insoluble starch
- Producing fat or oil storage
- Produce cellulose
- Producing amino acids
What mineral from the soil does a plant use to make amino acids?
Nitrate ions
What does respiration allow the plants to do?
To convert the rest of the glucose into useful substances for growth
Investigate how certain environmental factors change the rate of photosynthesis?
One adds PONDWEED to a SODIUM HYDROGEN CARBONATE solution in a boiling tube, (SHC releases CO2, which is necessary for photosynthesis)
Leave this for 5 mins in order to ACCLIMATISE to the conditions of the boiling tube
Gas will be produced in bubbles, (Product of photosynthesis is OXYGEN)
Count the number of bubbles per minute (find the mean) and reconduct the experiment at different distances from light source.
Record results and plot a graph.
Word equation for Respiration?
Glucose + Oxygen –> Carbon Dioxide + Water + Energy
What is cellular respiration?
An exothermic reaction which is continuously occurring in living cells, releasing energy
Why do organisms need energy?
- Chemical reactions, to build larger molecules
- Movement
- Keeping warm
What is anaerobic respiration?
The incomplete breakdown of glucose into LACTIC ACID
Glucose –> Lactic Acid
Gives far less energy than aerobic respiration
What is anaerobic respiration in yeast?
Fermentation
Glucose –> Ethanol + Carbon Dioxide
Why is fermentation important?
Has economic importance in the manufacture of bread and alcoholic drinks
How can the human body react to increased demand of oxygen?
- Heart rate quickens
- Breathing rate quickens
- Breath volume increases
What occurs in the body during vigorous exercises when insufficient oxygen is supplied to the body?
Anaerobic Respiration takes place
What happens when there is an incomplete combustion of glucose in the muscles?
- Build up of lactic acid occurs
- Causing muscles to not be able to contract efficiently due to fatigue
- Oxygen debt builds up
How does our body deal with oxygen debt?
- It can be oxidised to form CO2 and H2O
- Or blood flowing through the muscles can transport the lactic acid to the liver where it is converted back to glucose
What is metabolism?
The sum of all the reactions in a cell or the body
How can energy transferred by respiration in cells be used by the organism metabolically?
Used for continual enzyme controlled processes of metabolism that synthesize new molecules
What does metabolism include
- Conversion of glucose to STARCH, GLYCOGEN and CELLULOSE
- Formation of lipid molecules from glycerol and 3 molecules of fatty acids
- Use of glucose and nitrate ions to form amino acids (to synthesise proteins)
- Respiration
- Breakdown of excess proteins to form urea for excretion
What is a substrate?
- Temporarily binds to the active site of an enzyme
- Leads to a chemical reaction
How does the relationship with enzymes and substrates work?
- Both randomly move around in solution
- Enzyme and its complementary substrate collide randomly
- Enzyme-substrate complex forms, reaction occurs
- A product (or products) forms from the substrate which are released from the active site
How does temperature affect enzymes?
- Too low and the enzymes will not be effective and work too slow (less kinetic energy so lower rate of reaction)
- Optimum, and the enzymes will work at a good rate (collision theory)
- Too high, and enzymes will become DENATURED where the active site loses shape so substrates cannot lock on
What are the 3 main digestive enzymes?
Carbohydrases, proteases and lipases
What are proteases?
- Enzymes which break down carbohydrates into SIMPLE SUGARS
Such as amylase breaking down STARCH into MALTOSE, which is then broken down to glucose by MALTASE
What are proteases?
- Enzymes which break down proteins into AMINO ACIDS
What are lipases?
Enzymes which break down LIPIDS (fats) into GLYCEROL (and fatty acids)
