Unit 1
What are the steps of the scientific method in order?
Make observations
Ask a testable question
Form a hypothesis
Design & perform your experimental procedure
Collect & analyze data
Draw conclusions
Share your results
The atomic number if Sodium (Na) is 11 and the atomic mass is 23. How many neutrons does it have?
12 neutrons
Give an example of a molecule that can transport through the plasma membrane via simple diffusion.
carbon dioxide (small, nonpolar)
What are the equations for photosynthesis and cellular respiration?
photosynthesis: 6CO2 + 6H20 -> glucose + 6O2
cell resp: glucose + 6O2 -> 6CO2 + 6H20 + ATP
A scientist is looking at a cell under the microscope. They see nucleus, mitochondria, central vacuole, vesicles and cell wall. What type cell did the scientist conclude it to be?
Plant cell
What are the 8 characteristics of life?
1. Response to stimuli
2. Maintains homeostasis
3. Adapts over time
4. Grows & develops
5. Requires energy
6. Made of cell(s)
7. Reproduces
8. Levels of organization
Why can one enzyme not work on many different substrates?
Because enzyme substrate complex are specific and need to fit like lock and key.
You suspect you are looking at a bacterium under a microscope. What structures might lead you to think this?
DNA is not contained in a nucleus; DNA is circular
no membrane-bound organelles
What is the direct role of light in the light-dependent reactions of photosynthesis?
Light energy is captured by chlorophyll, and then used to split water into oxygen and create ATP and NADPH
What type of energy transfer takes place in cellular respiration?
Chemical energy of glucose is transformed into chemical energy of ATP.
What is the difference between a claim and a hypothesis?
A claim is supported by evidence AFTER the scientific method has been carried out
A hypothesis is what you think will happen (based on limited observations) BEFORE the experiment
What are the 4 major types of macromolecules, name their monomers, and an example of each?
nucleic acids - nucleotides - DNA
carbohydrates - monosaccharides - glucose
lipids - glycerol/fatty acids - phospholipids
proteins - amino acids - amylase
You place a cell in a solution of pure water. What happens to the cell and why?
The cell lyses (bursts). Water moves into the cell via osmosis (passive transport) because the water moves to the area of higher solute concentration inside the cells.
How does ATP release energy? And what are two differences between ATP and ADP?
When the bonds between the 2nd and 3rd phosphate groups is broken a lot of energy is released.
ATP has 3 phosphates and has higher energy, whereas ADP has 2 phosphates and has lower energy.
You got a new energy drink and you are curious about it. You test it's pH, which comes out to 3.5. Based on this information, how would you classify your energy drink?
Its acidic/ acid.
Scientists found a new entity. The only characteristics it has is it can grow, respond to stimuli, is organized and needs energy. Is this entity living and why/why not?
Non-living - Doesn't have all 8 characteristics of life.
Keeping enzymes in mind, why do you think it can be deadly if someone's body temperature stays above 102F for too long?
The enzymes will denature and slow down all chemical reactions in the body.
A cell needs to move a really large molecule into the cell against it's concentration gradient. Which process will the cell use to do so.
Endocytosis
How does a human muscle cell continue making ATP in a in absence of oxygen and what else does this process produce other than ATP?
lactic acid fermentation:
1. glycolysis: glucose -> 2 pyruvate + ATP + NADH
2. fermentation: 2 pyruvate -> lactic acid + NAD+
Which component of cell membrane is responsible for maintaining it's fluidity/rigidity with changing temperatures?
Cholesterol
You step outside in shorts and T-shirt, but the temperature is 23F. How will your body respond to maintain homeostasis?
Shivering/ goose bumps/ fend for warm clothes
Explain on a molecular level WHY ice floats in liquid water?
A cell has no difficulties making protein, but is unable to make any changes to the proteins or secrete them outside the membrane. A scientist hypothesizes that a defect in one of two structures could be responsible for this. What are the structures?
vesicles or the golgi apparatus
A scientist creates mutant cells that lack all transmembrane proteins. Which reactant/product of cellular respiration would be unable to get where they need to go as a result?
Glucose would be unable to get into cells
Polar molecules are moving down the concentration gradient into a cell. Which process are the cells using?
Facilitated diffusion