Cell Structure & Function
What researcher named the “cell” and what did he base it on?
What molecule is used to begin cellular respiration?
Glucose
Why are cells limited to a smaller size?
DNA overload demands of the cell, Membrane input and output overload
Whose observations lead to the discovery of microscopic creatures on a single cell level?
Antonie van Leeuwenhoek
How many ATP can be generated from one molecule of glucose?
2 ATPs
How does the ratio between surface area and volume change as a cell grows in size or is reduced in size?
As a cell gets bigger, the volume increases more rapidly than the surface area
What’s the difference between prokaryotes and Eukaryotes?
Prokaryotes have no nucleus, Eukaryotes do have a nucleus
How many steps are there to cellular respiration? Where does each of these steps happen in the cell?
3 steps: Glycolysis occurs in the cytoplasm, Krebs Cycle/Electron transport train-take place in the mitochondria
What is the difference between the end results of sexual and asexual reproduction?
End of sexual reproduction = offspring inherit genetic information from each parent
End of asexual reproduction = genetically identical offspring from a single parent
What is the cytoskeleton?
Helps cells maintain their shape and internal organization
Which step is anaerobic? Which step is clearly aerobic?
Glycolysis is anaerobic. The step that needs oxygen is the electron transport train but the Krebs cycle can’t happen without it
Explain the three stages of interphase, identifying specifically what is happening during each phase.
G1 phase: Cells grow, Synthesize additional proteins, Synthesize additional organelles
S phase (synthesis): Replicates (duplicates/copies) chromosomes
G2 Phase: Synthesize of additional/and organelles
What are the boundaries of a cell and how they differ between plants and animals?
Plant cells-cell wall, animals cells have a cell membrane
Which step produces carbon dioxide?
Krebs cycle
Explain the four stages of mitosis identifying specifically what is happening during each phase.
Prophase: Longest stage, Chromosomes condense (organize), Centrioles move to poles (think north pole/south pole), Nuclear envelope disappears, Spindle fibers attach to centromere, Nucleolus disappears
Metaphase: Centromere connects to the poles, Chromosomes line up on the equator
Anaphase: Centromere splits separating sister chromatids, Each chromatid is now considered an individual chromosome
Telophase: Chromosomes un-condense, Nuclear envelope (membrane) reforms, Spindle fibers break up, Nucleolus reforms (makes ribosomes), Centrioles disappear
Where does the fluid mosaic model get its name from?
A mosaic is a kind of art that involves bits and pieces and is very complex
What is oxygen (aerobic) used for?
It is an electron acceptor, which makes water
What is cytokinesis and how is it different between plants and animals?
Division of the cytoplasm
Plant cell-cell wall from cell plates
Animal- membrane pinches inward
The membrane is selectively permeable – what permeates it (passes through) and how?
Depending on the size and charge of ions, the membrane determines whether it can pass through or not
What does ATP stand for, what’s the difference between ADP and ATP, and which step produces most of the ATP?
Adenosine triphosphate
ADP becomes ATP in the Electron transport chain when the H+ are moving down the concentration gradient in the ATP synthase
Electron transport train
The timing of cell division is a function of internal and external regulators. Identify the regulators and how they do their job.
Internal: Cyclins
Respond to events occurring inside the cell, Regulates the timing of cell cycle in eukaryotic cells, Makes sure it proceeds only when certain events have occurred, One group of proteins
External: Glycoproteins
Respond to events occurring outside the cell, Directs the cell to speed up slow down the cell cycle, Protein made up of growth factors
Identify the two types of passive transport and differentiate between them.
Diffusion and Facilitated
Where do the electrons and hydrogen come from that are used in the electron transport chain?
NADH and FADH2
When do cells have to be replaced or added to?
Injury, Cell death, Growth
Differentiate and compare and contrast these terms: isotonic, hypertonic, hypotonic
How do you know that ATP synthase is an enzyme? What makes the ATP synthase turn?
Makes ATP from ADP and a third phosphate, -thase ending is how you know its enzyme
The ATP synthase turns from the H+ as they're moving down the concentration gradient
What is cell differentiation, and when a cell differentiates what is it becoming different from?
During development of an organism, cells become specialized. They become different from the embryonic cell(can produce any type of cell in the body) that produced it
When is the net movement across a semi-permeable membrane in an isotonic situation?
The barrier is permeable to water but not sugar. Water can cross, but sugar cannot
There is more sugar on the right; therefore, the concentration of water is lower on the right; therefore, the concentration of water is lower on the right, where more of the solution is made of sugar
What are the high-energy electrons used for?
The energy that is from the electrons NADH and FAD2 pumps the H+ into the space that is between the mitochondria’s inner and outer membrane
What is a stem cell and what makes them special?
Unspecialized cells from which differentiated cells develop
Name the two types of active transport that we covered.
Endocytosis, Exocytosis
How is the double membrane of the chloroplast used?
The outer membrane allows molecules to come in and out of the chloroplast and the inner membrane does not let some molecules come into the chloroplasts
What is the key difference between embryonic stem cells and adult stem cells?
Adult Stem cells: Rare, undifferenced cells present in tissues like-blood and skin
Embryonic stem cells: Capable of producing every cell type in the body, Can differentiate into nerve cells, muscle cells, etc.
Compare and contrast exocytosis and endocytosis.
Endocytosis-the process of capturing a substance or particle from outside the cell by eating it with the cell membrane, and bring it into the cell (2 types - phagocytosis and pinocytosis)
Exocytosis- the process of vesicles fusing with the cell membrane and releasing their contents to the outside of the cell
Why did the acquisition (Endosymbiotic Theory) of mitochondria into the cell provide an opportunity for the diversification of life?
It allowed a cell to take the oxygen from its atmosphere and use it to produce energy for certain processes
How might science use stem cells to treat people?
Inject adult/embryonic stem cells from the patient’s own bone marrow into their heart’s damaged area, or undifferentiated cells can be used to repair or replace damaged cells and tissues
What is homeostasis?
Maintains optimal conditions for enzyme action throughout the body and all cell functions
Why are stem cells caught up in an ethical tug of war?
The human embryonic stem cell research is controversial because the arguments for it and against it both involve ethical issues of life and death
When cells that grew from stem cells form their specific functions they are said to have specialized or differentiated. Why would they do this?
To maintain homeostasis
These daughter cells either become new stem or become specialized cells with a more specific function such as: Blood cells, Brain cells, Heart muscle cells, Bone cells
What are the levels of organization recognized by biologists?