Size and shape
What organelle contains the genetic information?
Nucleus
What is the site called that attaches the enzyme to the substrate?
Active site
What are the three types of passive transport and three types of active transport?
Passive: diffusion, osmosis and facilitated diffusion
Active: Ion pumps, endocytosis and exocytosis
What are the four main structures present in a mitochondria?
Inner membrane
Outer membrane
Cristae
Matrix
What is the term used to describe DNA replication?
Semi-conservative
What can happen if a cell get too large?
Nutrients cannot diffuse through to the centre of the cell quickly enough. It is more efficient to have a higher surface area to volume ratio.
Define an enzyme
Enzymes are BIOLOGICAL CATALYSTS, which means they speed up the chemical reactions involved in life processes.
Define a cell membrane
A semipermeable phospholipid bilayer that regulates the movement of substances in & out of the cell.
What are the two phases of photosynthesis?
Light-dependent phase and light-independent phase
What are the three main phases of the cell cycle?
Interphase - Prepares for division (G1, S and G2)
Mitosis - undergoes nuclear division
Cytokinesis - daughter cells separate
Why do some cells have specialised shapes?
This often occurs to increase their surface area-to-volume ratio. For example, the folded inner membrane of the mitochondria or the flat pancake-like structures inside chloroplasts provide a greater surface area on which specific reactions can occur.
Explain how an enzyme works
The enzyme binds to its substrate at a specific site called the active site, which lowers the activation energy required for the reaction to occur. The enzyme temporarily forms an enzyme-substrate complex, facilitating the transformation of the substrate into a product, and is then released unchanged, ready to catalyse another reaction.
What is the difference between active and passive transport?
Active transport requires ATP to move molecules from an area of low concentration to an area of high concentration (against the concentration gradient)
Passive transport move molecules from an area of high concentration to an area of lower concentration (along a concentration gradient)
What are the three steps of respiration? (state them in the correct order)
Glycolysis
Kreb cycle
Electron transport chain
Which of the following occurs in mitosis:
Independent assortment
Crossing over
Law of segregation
Trick question! None of them happens in mitosis; they only happen in meiosis!
Why do some cells have more of certain organelles than others?
This is because the cell has a specialised function that requires a high demand for a certain function of that organelle. For example, a muscle cell is going to require more mitochondria than other body cells, as muscle cells require high levels of ATP to function.
What are the five factors that can effect the efficiency of an enzyme?
Temperature
Enzyme concentration
Substrate concentration
Cofactors
Inhibitors
What are the three types of solutions?
Hypertonic - higher concentration of solutes outside the cell
Isotonic - equal levels of concentration of solutes inside and outside of the cell
Hypotonic - higher concentration of solutes inside the cell
What are the word equations for photosynthesis and respiration?
Photosynthesis
Water + carbon dioxide ------> oxygen + glucose
Respiration
Oxygen + glucose ------> water + carbon dioxide
Explain the steps of DNA replication
The original DNA strands are split in two, and each half is used as a template to make its complementary strand (the other half). Free nucleotides are base-paired with each template strand and linked together to make the complementary strands.
Define the term "diffusion distance"
Cells rely on diffusion to transport certain nutrients and wastes in and out of the cell. If there is a shorter distance for the nutrients or waste to travel, then the rate of diffusion will be faster.
What is a cofactor?
A non-protein chemical compound that is required for the enzyme to function properly.
If a cell is placed in a hyper tonic solution what will happen to it?
Hypertonic solution means there is a higher concentration of SOLUTES outside the cell.
The lower concentration of water outside the cell causes next movement of water out of the cell. In animal cells this makes the cell shrivel up (crenate) In plant cells the membrane tears away from the cell wall (plasmolysis)
What 5 factors can affect the rate of photosynthesis and respiration? (Some effect one and not the other)
Wavelength of light (photosynthesis)
Substrate concentration (oxygen or carbon dioxide)
Cofactors/inhibitors
Temperature
pH
What are the factors that affect the rate of mitosis?
Stage of life
Cell type and location
Availability of nutrients and energy
Enzymes (this includes pH, temperature, substrate concentration, enzyme concentration, inhibitors and cofactors)