Unit 3 Review Flashcards
process of aerobic respiration
- Glycolysis breaks down glucose in the cytoplasm into ATP and pyruvate,
Glucose is phosphorylated (using ATP), Lysis (splits into 2 molecules), each molecule is oxidized by NAD+ (NAD+ becomes NADH), ATP is formed (net gain = 2), creates 2 pyruvate molecules - Pyruvate is actively transported into the mitochondrial matrix where it is decarboxylated and combines with coenzyme A in the link reaction to produce CO2, NADH + H+, and acetyl CoA
- Acetyl CoA enters the Krebs Cycle in the matrix – the Krebs Cycle decarboxylates substrates to produce CO2, substrates are oxidized to provide electrons to NAD+ and FADH (they become NADH and FADH2), and substrate-level phosphorylation produces 2 ATP
- NADH and FADH2 donate electrons to the electron transport chain (in the cristae/ inner mitochondrial membrane). Electrons pass down the chain to oxygen, the final electron acceptor. Oxygen, electrons, and hydrogen ions combine to form water.
- Proteins in the electron transport chain use the energy from electron movement to pump H+ ions from the matrix into the intermembrane space (creating a hydrogen ion concentration gradient).
- In chemiosmosis, H+ ions flow DOWN their concentration gradient (from the intermembrane space to the matrix) through ATP synthase proteins (in the cristae/ inner mitochondrial membrane). ATP synthase uses the energy from H+ movement to combine ADP + Pi, making ATP (34 ATP).
light dependent reactions
- Light is absorbed by pigment chlorophyll a (blue and red absorbed; green reflected)
- Photolysis: light energy used to split water molecule to supply electrons to photosystem II (PSII)
Oxygen gas is given off as a byproduct - Light absorbed by PSII “excites” electrons (and they “jump” to a higher energy level)
- Excited electrons from PSII “caught” and delivered to an electron transport chain (#1)
- Electrons move down the chain to photosystem I (PSI)
Movement of electrons used to pump H+ ions from the stroma INTO the thylakoid
Chemiosmosis: H+ ions move DOWN their concentration gradient (back into the stroma) through ATP Synthase proteins, generating ATP (Photophosphorylation – LIGHT powers the electron transport chain which aids in ATP production) - Light absorbed by PSI “excites” electrons (and they “jump” to a higher energy level)
- Excited electrons from PSI “caught” and delivered to an electron transport chain (#2)
- Electrons move down the chain to NADP reductase, which reduces NADP+ to NADPH+
light independent reactions
- Carbon Fixation
Enzyme Rubisco adds CO2 (inorganic) to RuBP (5C compound) – “fixing” it (making it part of an organic compound)
6C compound is unstable and splits into two 3C compounds (G3P = glycerate-3-phosphate = first identifiable/ measurable product of carbon fixation/ light-independent reactions) - Reduction
G3P reduced to triose phosphate sugar by NADPH from light-dependent reactions (NADPH back to NADP+ again)
Requires ATP (from light-dependent reactions) - Regeneration of RuBP
(Most) Triose phosphate and ATP used to regenerate RuBP
(Some) Triose phosphate used to make/ store glucose (starch)
limiting factors in photosynthesis
Temperature
As temp increases the rate of photosynthesis increases too because enzymes have more collisions with substrates
If the temp gets too high enzymes denature and rates decrease
Light Intensity
As light intensity increases the rate of photosynthesis increases until the pigments/photosystems become saturated and the rate plateaus
CO2 Concentration
As CO2 concentration increases the rate of photosynthesis increases until Rubisco is saturated and the rate plateaus
These factors would need to be held constant in a photosynthesis experiment if they are not being tested as the IV
ATP is also a limiting factor because more of it required for light-independent reactions than CO2 or NADPH
Mitochondria structure
Inner membrane (cristae) Folded – increases SURFACE AREA for electron transport chains/ ATP Synthase/ chemiosmosis/ oxidative phosphorylation
Intermembrane space
Small – allows for rapid build up of H+ ions (protons) to create a gradient
Matrix (FLUID)
Fluid = Contains appropriate enzymes and pH for link reaction and Krebs Cycle
Outer membrane
Separates mitochondria from rest of cell and contains appropriate proteins to shuttle pyruvate into matrix from cytoplasm
Chloroplast structure
Thylakoids (small, disc-shaped structures)
Small lumen/ space inside – allows for rapid accumulation of protons (H+)
Grana (stacks of thylakoids)
Thylakoids in stacks – increases surface area for light absorption (more photosystems with chlorophyll)
Stroma (fluid within the chloroplast/ OUTSIDE of thylakoids)
Contains appropriate enzymes and pH for light-independent reactions
Double membrane (inner and outer membranes – from endocytosis) Isolates enzymes etc. from other parts of plant cell
Absorption spectrum
the amount of each wavelength absorbed by each pigment in photosynthesis
Action spectrum
the RATE of photosynthesis for each wavelength of light absorbed
Fatty acid structures and health effects
Carbon chain with COOH at one end
Saturated fats - Linear/ straight (no C=C double bonds) - Animal fats are saturated fats - Diets rich in contribute to CHD, high LDL cholesterol, atherosclerosis, hypertension, obesity, clots/ thrombosis
Unsaturated fats
- Healthier
Trans fats
- Not good for you
- Do not occur naturally and the body doesn’t know how to process them
Carbohydrate energy storage
Stored as glycogen (animals) and starch (plants)
Glycogen and starch are hydrolyzed to glucose when energy needed
Short-term energy storage (disrupt osmotic balance of tissues in large quantities)
Lipid energy storage
Stored as triglycerides (in adipose cells in liver/ muscle tissue)
Triglycerides are hydrolyzed to glycerol and fatty acids when energy needed
Long-term energy storage (hydrophobic, so do not disrupt osmotic balance and can be stored for long periods of time)
Twice the energy content of carbohydrates
(-Lipids = 9 calories per gram
-Carbohydrates = 4 calories per gram)
Note: Proteins also contain 4 cal/ gram
Types of carbohydrates
Monosaccharides
- Glucose, galactose, fructose
Disaccharides
- Maltose, lactose, sucrose
Polysaccharides
- Starch, glycogen, cellulose
Measuring rates of photosynthesis
Direct
- Oxygen production: from light-dependent reactions (count bubbles/ measure dissolved oxygen in water)
- CO2 uptake: Calvin cycle (measure pH of water; more CO2 taken into plant = increase in pH of water)
Indirect
- Biomass Increase: more sugars = more tissues/ growth/ more stored carbohydrate
BMI formula
Kg / m^2 or lbs / in^2 * 703
Chromatography process
A mixture is dissolved in a fluid (called the mobile phase) and passed through a static material (called the stationary phase)
The different components (pigments) of the mixture travel at different speeds (due to variation in size/ polarity etc.), causing them to separate
A retardation factor can then be calculated
Rf value = distance pigment travels ÷ distance solvent travels
Different pigments have different Rf values and can be used to identify pigments
