Cell Structure Study Guide KEY

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Pre-AP Biology – Cell Structure and Function Study Guide - KEY

1.

Label the following microscopes and know the function of each part. (You do not have to write the functions for your review, but you will be required to know them for your test.)

1. Body tube, 2. revolving nosepiece, 3-5. objectives, 6. stage clips, 7. diaphragm, 8. light source, 9. ocular lens, 10. arm, 11. stage, 12. coarse adjustment knob, 13. fine adjustment knob, 14. base

2.

What is the cell theory (definition)? cells are the basic unit of structure in function in all living organisms

3.

What are the 3 parts of the cell theory?

All living organisms are composed of one or more cells.

The cell is the most basic unit of life.

All cells arise from pre-existing, living cells.

4.

List and define the levels of life’s hierarchy from an atom up to a single organism. (These notes are from unit 1. If you no longer have them, they can be found on the online classroom).

Least specific (biggest thing)

Biosphere – All environments on Earth that support life (Basically, the Earth and the sky above it that has living things occupying it.)

Biomes – A group of ecosystems that have similar climates and communities

Ecosystem – all living organisms in a particular area as well as the nonliving, physical components they interact with (ex. Sunlight, water, etc.)

Community – All living things in an area

Population – Single species living in a single area

Organism – Single individual

Organ System – group of organs working together for a certain function

Organ – 1 part of an organ system

Tissue – group of similar cells that do a particular function for an organ

Cell – Smallest unit of life (All living things are made up of one or more cells) (Can perform all

7 characteristics of MRS. GOCH)

Organelle – “organ” of a cell

Molecule – cluster of atoms held together by chemical bonds

Atom - basic unit of matter made of dense nucleus (protons and neutrons) with electron cloud around it

Most specific (smallest thing)

5.

Be able to identify all organelles of plant and animal cells and tell their function. Text pgs. 56-57

6.

What are the functions of the following organelles? These are only some examples of what could be on the test. Question #3 tells you that you need to know them all, but this question is just to ensure that you studying this information. a. Lysosome – digestion and break down of waste b. Smooth and Rough ER – in general, transport of proteins through the cell before they are exported (but there are many more) c. Ribosomes – site of protein synthesis

d. Peroxisomes – break down oxygen containing waste e. Nucleus – holds DNA which codes for proteins that will control the rest of the cell f. Golgi Body – packages and organizes proteins before they are exported from cell g. Mitochondria – production of ATP h. Chloroplast – site of photosynthesis (production of glucose) in photosynthetic eukaryotes

7.

Be able to identify all the parts of a prokaryotic cell and tell their function (Text pg. 55).

8.

What is cellular respiration? (Hint: Look at the function for mitochondria. We will study this process in detail later so you do not need to know specifics about it right now. You simply need to know what the process is.)

Using the energy stored in glucose to make ATP

9.

How are mitochondria different from chloroplasts?

Chloroplast make glucose( food). Mitochondria make ATP from this glucose.

10.

What is the nucleolus?

Dark spot in nucleus where ribosomes are made.

11.

What is a nucleoid region? What type of cell has a nucleoid region?

Prokaryotes have a nucleoid region because they do not have a nucleus. It is the area in the cytoplasm where their DNA is located.

12.

What are the 3 types of fiber that makes up the cytoskeleton? Which is the biggest and smallest? microtubule (biggest), intermediate filament, microfilament

13.

Describe the functions of microfilaments & microtubules. Give an example of where each is found. microtubule = INTRAcellular movement microfilaments = movement of the entire cell

14.

What is the function of the ECM?

INTERcellular communication, Holding cells together in tissues

15.

What type of cells are centrioles found in (animal, plant, or prokaryotic), and what are they for? animal cells; to anchor spindle fibers during cell division

16.

How are cilia and flagella different?

Both are used for movement. Cilia are short and there are many of them. Flagella are long and there are only a few of them.

17.

What are the 3 types of cell junctions? Explain the function of each.

Gap = movement of things between cells

Tight = holding cells together so nothing leaks out (Ziploc bag)

Anchoring = Holding cells in a tissue together (door hinge)

18.

Provide examples of where each type of junction might be found.

Gap = any cells that secretes products

Tight = stomach cells

Anchoring = skin cells

19.

What are plasmodesmata? What type of cell is it found in?

Plasmodesmata are the gap junctions of plants.

20.

Which type of cell junction is plasmodesmata most like?

Gap junctions

21.

What type of cell would each of the organelles be most abundant: a. mitochondria – Muscles (Anything that would require lots of energy) b. Rough ER – Pancreas (Anything that secretes something for other cells to use. i.e. Pancreas secretes insulin and glucagon) c. Smooth ER – Liver (lots of enzymes in smooth ER so anything that involves breaking things down) d. lysosome – white blood cells (lysosomes break down waste and old food. White blood cells break down pathogens and lysosomes are what actually does this). e. tight junction – stomach cells (tight junctions hold in material so this would keep acids from leaking out of stomach)

22.

What is the largest organelle in a plant cell?

Central Vacuole

23.

Order cells from largest to smallest (animal, plant, bacteria) plant (cell wall), animal (no cell wall), bacteria

24.

List 3 differences between prokaryotic and eukaryotic cells.

Prokaryotes = no nucleus, no membrane bound organelles, unicellular (most eukaryotes are multicellular but not all)

25.

What are 5 things that all cells must have (prokaryotic and eukaryotic) and why?

DNA – code for proteins

Ribosomes – to make proteins that are coded for by DNA

Proteins – to be the workhorse of the cell

Cell membrane – to be selectively permeable (choose what comes in and out of a cell)

Cytoskeleton – the skeleton of the cell to keep its form and allow movement

26.

How is a cell wall different from a cell membrane (plasma membrane)?

Cell wall is rigid and for protection. Cell membrane is fluid and decides what comes in/out of the cell.

27.

What type of cell has a cell membrane (animal, plant, or prokaryotic)?

Every cell must have a cell membrane

28.

What type of cell has a cell wall (animal, plant, or prokaryotic)?

Plants (made of cellulose) and prokaryotes (not made of cellulose) – Animal cells do not need cell walls because it would limit their mobility

29.

Does a plant cell have mitochondria? Why?

Yes, even though they have chloroplast to make their own glucose they must still convert that glucose to ATP.

30.

Does a plant cell have centrioles? Why?

No, their spindle fibers can attach to the cell wall during cell division.

31.

What is the function of a glycoprotein (found in the cell membrane)?

I.D. badge – identify the type of cell to recognize yourself from an invader and for cells of the same type to join together in tissues

32.

Why is RNA important for protein synthesis? mRNA takes the code from DNA to the ribosomes rRNA is what ribosomes are actually made of tRNA brings in amino acids to build proteins

33.

Where are ribosomes made? Where are they found? What do they make? nucleolus; cytoplasm or rough ER; proteins

34.

How does food within a food vacuole get digested? lysosome

35.

What is apoptosis? programmed cell death (to kill diseased cells or during development – like in between your fingers and toes)

36.

What are 3 organelles found in a plant cell and not an animal cell? chloroplast – photosynthesis to make glucose central vacuole – store water cell wall – made of cellulose and used for extra protection

37.

Why does a plant wilt? central vacuole loses water

38.

What is endosymbiosis? creation of eukaryotes from prokaryotes (specifically mitochondria and chloroplast).

Larger prokaryotes engulfs smaller prokaryote --- both benefit (small gets protection and big gets energy from small) ---- remain together during asexual reproduction (binary fission) --become 1 organism

39.

List 3 pieces of evidence that supports endosymbiosis.

Mitochondria and chloroplast both have:

1) their own DNA

2) their own ribosomes that are smaller (like prokaryotes)

3) both divide by splitting in 2 (like binary fission)

4) both have 2 membranes

Pre-AP Cell Membrane Study Guide - KEY

1.

Why were phospholipids so critical in the formation of the first cells?

Cell membranes are made of phospholipids. They are what allow the inside of the cell to remain separate from the outside environment.

2.

What does the “fluid mosaic model” explain?

Fluid – cell membranes actually move because of the unsaturated fatty acid tails

Mosaic – cell membranes are made of many different parts (phospholipids, proteins, cholesterol)

3.

List 4 functions of proteins found in the cell membrane.

Enzymes – speed up reactions

Glycoproteins – I.D. badges

Receptor proteins – receive signals from outside the cell

Transport proteins – move larger or polar solutes into and out of the cell

4.

List the 3 types of transport proteins and describe them.

Channel – move polar/ionic molecules down their concentration gradient

Pump – move polar/ionic molecules against their concentration gradient

Carrier – bind to one (or a few) specific molecules and move then individually across the membrane; much slower than channel protein

5.

Why are glycoproteins important to the immune system?

Let your body tell the difference in your cells and bacteria/viruses

6.

What does selective permeability mean?

Some things are allowed in/out of the cell but not everything

7.

Explain how the fact that transport proteins have a shape that fits a specific solute aids the cell in being selectively permeable.

Only certain solutes can come through transport proteins. Not everything outside the cell can come in.

8.

Why do receptor proteins have a shape that fits a specific messenger?

Each receptor protein will only receive 1 kind of messenger. This allows the body to know that when it releases a message that it will only be picked up by the cells that need it.

9.

How does a glucose molecule cross the cell membrane? How about ions?

Through transport proteins (both are large and have charges)

10.

What is a “concentration gradient” and what is going “down or with” it and going

“against it”?

Difference in concentration across a cell membrane.

Going down the concentration gradient = going from high to low

Going against concentration gradient= going from low to high

11.

What does tonicity refer to?

The ability of a solution to make a cell gain/lose water

12.

Explain the movement of water if a cell were placed in a…

Hypertonic – Water leaves the cell (cell shrivels up like a skinny hyper kid)

Hypotonic – Water enters the cell (cell swells up like a fat hippo)

Isotonic – Water enters and leaves at the same rate

13.

What type of solutions do plant & animal cells prefer? plants = hypotonic (so they can gain water and be turgid – they have central vacuoles to store water) animals = isotonic

14.

If an animal cell is placed in a hypotonic solution for too long, what will happen to it?

What prevents a plant cell from doing this?

Animal cell would lyse (burst). Plant cell has a cell wall that resists pressure (and a central vacuole to store water)

15.

When a plant cell is in a hypotonic solution, it is not flaccid, but ___turgid__________.

16.

If solution A has a higher concentration of solute than solution B, what will move (solute or water) and which direction if diffusion is occurring?

From A to B (it will go down it’s concentration gradient – more solute in A than B

17.

If solution A has a higher concentration of solute than solution B, what will move (solute or water) and which direction if osmosis is occurring?

From B to A (water will go down its own concentration gradient – there is more water in B than in A)

18.

List 2 differences between active & passive transport.

Passive = no energy (ATP) and down the concentration gradient

Active = energy (ATP) and up the concentration gradient

19.

List and define the 3 examples of passive transport.

Diffusion – movement of small, nonpolar molecules directly across the phospholipid bilayer going down their concentration gradient

Facilitated Diffusion – movement of larger or polar molecules across transport proteins going down their concentration gradient

Osmosis – movement of water through aquaporins (transport proteins for water) going down its own concentration gradient (will be the opposite direction of diffusion)******

20.

Give 2 similarities and 1 different between diffusion and facilitated diffusion.

Both require no energy because they are going down their concentration gradient

Diffusion occurs directly across the phospholipid bilayer where facilitated diffusion occurs through transport proteins

21.

Give 1 similarity and 2 differences between facilitated diffusion and active transport.

Both use transport proteins

Differences = facilitated diffusion requires no energy and goes down its concentration gradient while active transport requires energy and goes against the concentration gradient

22.

Why do some molecules have to use vesicular transport to enter or leave the cell?

The molecule is too big to fit through a transport protein (For example, if a protein is coming into or out of the cell then it would be too big to fit through another protein)

23.

Endocytosis is a type of vesicular transport. Give three examples of endocytosis, and explain each.

Phagocytosis – “cellular eating” A cell engulfs a particle by wrapping extensions called pseudopodia around it and packaging it within a vacuole.

Pinocytosis – “cellular drinking” A cell gulps droplets of fluid into tiny vesicles.

Receptor – mediated endocytosis –

Receptor proteins for specific molecules are embedded in cell membrane.

These receptors have picked up particular molecules.

Then the cell membrane pinches off to form vesicle containing receptors and their attached molecules

24.

What is signal transduction?

After a receptor protein receives a signal, signal transduction pathway occurs which is a series of steps to turn on a process inside the cell.

25.

Be sure to be able to identify and explain the functions of all of the components of the cell membrane. Use diagram to the right.

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