Review of Basic Chem & Cell Biology Flashcards
Explain how failure to regulate the cell cycle can lead to tumors and cancers
- when mutations occur in the cell regulation, this can cause regulation to fail
- the cell does not have the signal to stay in interphase and abnormal cell division begins
- cell division is uncontrolled and accelerated which causes the formation of tumors/neoplasm
- if/when the tumor breaks through the tissue boundary, it can enter the bloodstream and spread
- only then can the tumor turn to cancer
- benign tumors are NOT cancerous, but MALIGNANT tumors are cancerous
Distinguish between tumour and a cancer
a tumor is occurs when there is abnormal cell division (due to disrupted cell regulation)
cancer indicates a tumor, but a tumor is not always cancer
A TUMOR IS NOT A CANCER….
- they can become cancers, but tumors are not defined as cancers until the boundaries of the tumor break through the boundaries of the original tissue
- as the cells break through the tissue layer or leave the original tumor and get into the bloodstream to spread, then it is a cancer
What are the six different ways that molecules and ions can move across the cell membrane?
free diffusion,
osmotic flow,
passive vs active transport,
primary vs secondary active
transport
What is free diffusion?
a form of PASSIVE TRANSPORT
- no ATP required
- no protein assistance required
- molecules move freely across the membrane by their concentration gradient
*What is osmotic flow?
a form of PASSIVE TRANSPORT (osmosis)
- no ATP required
- movement of water down their osmotic gradients
- causes changes in volume
- osmotic pressure/force can prevent water from moving
What is passive transport?
Passive transport allows substances to move according
to their concentration (or electrochemical) gradients.
What is active transport?
Active transport uses stored energy to move ions
or molecules against a concentration gradient.
Differentiate passive transport from active transport
passive transport does not require ATP energy as molecules just move DOWN their concentration gradient
active transport requires ATP energy because molecules are moving AGAINST their concentration gradient
What is primary active transport?
- involves ATP being directly broken to move particles against their concentration gradient
“pump” protein directly breaking ATP itself to move molecules against their gradients (Na+/K+ ATP pump)
- if you see ATP being broken
What is secondary active transport?
- uses a gradient of one molecule (created using ATP) to move another molecule, but there is no ATP being directly broken =
- uses energy from the concentration gradient
no ATP being broken directly (transported using the energy from a concentration gradient of another molecule) - co-transport
What is the difference between primary and secondary active transport?
primary active transport DIRECTLY BREAKS DOWN ATP to get the energy for active transport
secondary active transport DOES NOT DIRECTLY BREAK DOWN ATP - instead it uses the gradient created by another particle
“In primary active transport, the energy is derived directly from the breakdown of ATP. In the secondary active transport, the energy is derived secondarily from energy that has been stored in the form of ionic concentration differences between the two sides of a membrane.”
Describe the five characteristics of water
- solvent - due to water’s polar nature, it is able to dissociate ionic compounds in solutions
- lubricant - since water molecules have little friction, it can be used as a lubricant between joints to reduce friction (joint fluid)
- facilitates chemical reactions - can be used as a reactant or produced as a product (dehydration synthesis or hydrolysis)
- high heat capacity - because of the hydrogen bonds, water can absorb great amounts of heat before changing forms (can absorb large amounts of energy without a great change in temperature)
- high heat of vaporization (sweating and cooling down) - surface tension - water molecules are COHESIVE, so they have a strong tendency to stick together
What is an organic compound?
a compound containing carbon, hydrogen, and usually oxygen
- carbon has 4 valence electrons and can form 4 bonds
What are the four different functional groups?
- amine -NH2
- phosphate -(PO4)2-
- carboxyl -COOH
- hydroxyl -OH
What are the four main categories of macromolecules (their monomers and polymers)
- carbohydrates (glucose, disaccharides, glycogen, starch, cellulose)
- lipids (fatty acids, glycerol, neutral fats, steroids, phospholipids)
- proteins (amino acids)
- nucleic acids (nucleotides - DNA, RNA, ATP)
Review: what is negative feedback and what is positive feedback?
negative feedback = a method of homeostatic regulation where the response triggered shuts off the initial stimulus (provides stability and linked with homeostasis)
positive feedback = accelerates a process, where the response triggered enhances or amplifies the original stimulus (moves conditions farther from the initial set-point)
