BIO 101 Exam 3 Review Flashcards
How many chemical bonds does one glucose molecule has?
24 chemical bonds
Glucose molecules are bonded into larger units called starch or glycogen
Energy needs for living things
Mechanical work Electrical work Active transport Bioluminescence Heat Biosynthesis
Glucose
The major form of stored chemical energy in living organisms
Stored in plants as starch; stored in animals as glycogen
Cellular respiration
Th process by which cells produce ATP
Chemical bonds of glucose are broken and the energy in them transferred to ATP
Occurs in all body cells
Laws of thermodynamics
- Total energy is neither lost nor gained during energy transformations
- Spontaneous energy transformation always involve a decrease in useful energy of the system and an increase in useless energy (entropy) of the surrounding
Why is diffusion a spontaneous process?
Because it leads to more disorder
Why is the synthesis of starch from glucose not spontaneous?
Because it leads to more order
Endergonic process
Not spontaneous
It is work and requires an input of energy
Exergonic process
Do not require energy. Releases potential energy and will occur spontaneously under the proper circumstances. I.e, breakdown of ATP to ADP.
Entropy
a measure of the amount of disorder in a system. This is useless energy; it can’t accomplish work
Breakdown of ATP to ADP
When ATP breaks down to ADP + Pi (phosphate group), 8 kilocalories of energy is released
Phosphorylation
The addition of a phosphate group to an organic compound such as ADP
Dephosphorylation
The removal of a phosphate group from an organic compound such as when ATP breaks down into ADP + Pi
Reduction in terms of useful energy
The gain of an electron(s)
Oxidation in terms of useful energy
The loss of an electron
Respiration
Occurs partly in the cytoplasm and partly in the mitochondria
Fermentation
An anaerobic process through which ATP is produced.
It is less efficient compared to aerobic respiration.
It does not require oxygen gas.
Steps involved in Fermentation
Glycolysis and one or two additional enzyme-catalyzed steps
Steps in aerobic respiration
- Glycolysis
- Citric Acid Cycle (Kreb’s Cycle)
- Electron Transport Chain
Glycolysis
The metabolic pathway that converts glucose into pyruvate
It occurs in the cytosol and does not require energy. Produces 2 ATPs
Citric Acid Cycle
Occurs in the matrix of the mitochondria, may be contingent upon the presence of oxygen.
Produces 2 ATPs
Electron Transport Chain
Occurs in the cristae of the mitochondria. Absolutely requires O2 to operate and produces 32 - 34 ATPs. This process is called chemiosmosis
The process of Glycolysis
The production of 2 pyruvates as a result of the breakdown of one glucose molecule results in the release of energy that phosphorylates 2 ADPs to 2 ATPs.
Decarboxylation
The process by which carbon is removed in the form of CO2 during the conversion of C3 to C2 in the Electron Transport chain.
Citrate
The combining of C4 with C2 to form a C6 compound
What happens to NAD+ and FAD when they accept hydrogens during EAC?
They become reduced to NADH+ H+ and FADH2 which enters the cytochrome system
What happens when molecules of NADH+H+ and FADH2 transfer hydrogen atoms to the cytochromes?
They are oxidized to NAD+ and FAD
In breaking down lipids to provide energy, what happens?
Lipids - fatty acids + glycerol
Fatty acids are broken down into two carbon units which is converted into acetyl-CoA and fed into the citric acid cycle. Glycerol is converted into another C3 compound which enters glycolysis.
Deamination
The removal of the -NH2 (amino group) as ammonia. It permits the C2+C3 fragments to enter the Citric Acid Cycle
How is the body designed to process starch, carbohydrates and fats for energy?
carbohydrates, fats, protein. The last type of molecule used for energy would be protein and would be harmful
Why are lipids more energy rich than carbohydrates?
Lipids are more reduced than carbohydrates, i.e., they have more hydrogen per carbon atom
Ectothermic
Cold-blooded organism
What would be the effect of increase or decrease on the activities of frogs, fishes, trees?
A temperature increase would increase the activity of all. The reverse would be true for a temperature decrease.
Homeothermic
Warm-blooded (mammals and birds). Uses heat lost by cellular respiration to regulate their own temperature
How does the temperature of mammals and birds compare with the surrounding environment?
May be different, they maintain a relatively constant body temperature that may be either higher or lower than the temperature of their environment
What is hibernation?
Periods of very low metabolic rate
Phases of photosynthesis
Light dependent phase - carried out in the membrane structures of the thylakoids.
Light independent phase - believed to occur in the stroma
What advantage is there to physical separation of the light dependent and light independent phases of photosynthesis?
The separation allows light capture and the machinery associated with it to be separated from the reduction of carbon dioxide to glucose.
In what ways are membranes useful in performing complex biochemical reaction?
Membranes provide an attachment surface for molecules so that specific enzymes, pigments, or electron carrier molecules can be arranged in specific order along a membrane.
Which wavelengths are best absorbed by chlorophyll?
Waves 400 to 500 nanometers in length (violet-blue) and waves 625 to 700 nanometers in length (orange-red).
What agent initially captures the sunlight (radiant) energy?
Electron of chlorophyll molecule
How is captured energy in photosynthesis used to form NADPH+H^+?
Two “excited” electrons (two photons of light are required) from chlorophyll along with two hydrogen ions(created from the photolysis of water) are used to reduce NADP+ to NADPH + H+.
What is photolysis?
Photolysis is the splitting of the water molecule into hydrogen ions (protons), electrons, and oxygen gas.
What is the relationship between light energy and photolysis?
Light energy is required for photolysis.
How is light energy involved in creating a high H^+ concentration inside the thylakoid discs?
As the “excited” electrons created by photons move from one carrier molecule to the next along the thylakoid membrane, the energy that is released is used to pump protons (H ions) into the thylakoid space.
The protein gradient is used to generate______
ATP
The two energy rich products that are present at the end of the light reaction are_____and____
ATP and NADPH + H+
