Bio 11- lab 4 -cell stucture and function PDF

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Bio 11- Lab 4 – Cell Structure and Function – lab questions, review, and though questions !!!...

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Bio 11- Lab 4 – Cell structure and Function – lab questions, review and though questions !!! 

Plant cells o Cell wall o Chloroplast

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Animal cells o Centrioles in centrosome

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Plasma Membrane- Controls movement of substances in/out of cell

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Nucleus - Contains DNA molecules and nucleolus

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Nucleolus- Assembly site for ribosomes

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Ribosomes- Site of protein synthesis

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Endoplasmic reticulum- synthesis and/or modifies proteins and other substances; transport by vesicle formation

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Rough er – er with ribosomes- protein synthesis

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Smooth er- er without ribosomes- synthesis of lipid molecules

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Golgi apparatus- process, package, and distributes protein and lipids

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Vesicles- stores and transports substances

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Lysosomes- Enzymes digest and recycle worn out organelles and substances entering the cell; can digest the cell

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Mitochondria- Makes ATP via aerobic cellular respiration

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Centrosomes (centrioles)- Form mitotic spindle; needed to form cilia and flagella

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Cytoskeleton- Three kinds of protein filaments; maintain cell shape and involved in cell movement and movement of organelles

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Cell wall- provides support and protection

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Central vacuole(large)- stores and transports substances

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Chloroplast – carries out photo synthesis producing sugars – it also gives plants it green color

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Can you locate the cell nucleus? Answers will vary, but usually yes

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Why can't you see the other organelles featured in Figure 4.2. A light microscope does not permit seeing them; an electron microscope would be needed.

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Inn which experiment was diffusion the fastest? Air

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What accounts for the difference in speed? Air is less dense the other options

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Bag – no color in the beginning

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Bag color at the end – blue – black

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Bag conclusion iodine diffused into the bag

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Beaker color before yellowish

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Beaker color at end- less yellow

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Benedict’s test for beaker – positive

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Beaker conclusion- solute diffusion across plasma membrane

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Which solute did not diffuse across the dialysis membrane from the bag to the beaker? starch

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How do you know. The solution in the beaker did not turn blue-black.

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Note the level of liquid in the thistle tube, and measure how far it travels in 10 minutes: 1 mm

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Calculate the speed of osmosis under these conditions: 6 mm/hr

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In which direction was there a net movement of water? from beaker to thistle tube

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Explain what is meant by “net movement" after examining the arrows in Figure 4.66. Water moves in and out of thistle tube, but more water moves in than moves out of tube.

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If the starch molecules in corn syrup moved from the thistle tube to the beaker, would there have been a net movement of water into the thistle tube? No

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Why wouldn't large starch molecules be able to move across the membrane from the thistle tube to the beaker? They are too large to cross a membrane.

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Explain why the water level in the thistle tube rose: In terms of solvent concentration, water moved from the area of higher

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water concentration to the area of lower water concentration across a differentially permeable membrane.

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Tube 1 o Isotonic o No effect o No o Cells are intact

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Tube 2 o Hypertonic o Cells lose water o No o Cells are intact

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Tube 3 o Hypotonic o Cells gain water o Yes o Cells have burst

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Hypotonic o Normal o Due to turgor pressure

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Hypertonic o Shriveled center o Due to Plasmolysis

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Which tube has the limp potato strip? tube 2

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Use tonicity to explain why water diffused out of the potato strip in this tube.? The solution in tube 2 was hypertonic.

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Which tube has the stiff potato strip? tube 1

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Use tonicity to explain why water diffused into the potato strip in this tube? The solution in tube 1 was hypotonic.

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Tube number 1 – content water and potato- tonicity hypotonic – result was stiff potato- explanation is that the water diffused into the potato strip

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Tube 2- content was salt solution and potato strip – tonicity was hypertonic- results were the limp potato strip- explanation was that the water diffused out of the potato strip

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In a hypotonic solution, animal cells swell to bursting.

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In red blood cells this is called hemolysis.

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In a hypertonic solution, animals cells shrivel.

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In red blood cells this is called crenation.

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In a hypotonic solution, the central vacuole of Elodea cells exerts turgor pressure,

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and chloroplasts are seen next to the cell wall.

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In a hypertonic solution, the central vacuole loses water and plasmolysis

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occurs. The cytoplasm plus the chloroplast are seen in the center of the cell.

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In a hypotonic solution, potato strips gain water;

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in a hypertonic solution, potato strips lose water and become limp.

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Why are cells and organisms buffered? to maintain pH of the cells

tube 1 2 3 

Contents

Ph before

Ph after acid Explanation

Water Buffer Cytoplasm

acid 6-6.5 7 7

2-3 7 7

Not buffered Buffered Buffered

Why would you expect cytoplasm to be as effective as the buffer in maintaining pH? Living things are buffered.

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Did dosage in mg have any effect on the results? depends on antacid used

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Which of the substances on the label could be a buffer? depends on antacid

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what regulates the movement of molecules into and out of the cytoplasm? plasma membrane

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what kind of cells lack a nucleus? prokaryotic cells

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what structures associated with prokaryotic and eukaryotic cells carry out proteins synthesis? ribosomes

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what two things are found in the nucleus of a eukaryotic cell? Dna and nucleus

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what plant cell organelle carries out photosynthesis? chloroplast

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what molecule is associated with plant cell walls? cellulose

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what energy (ATP) prodding organelles is found in animal and plants cells?

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Mitochondria

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what is the movement of molecules from an area of higher to lower concentration called? diffusion

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what is the movement of water across the plasma membrane called? osmosis

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does water move into or out of cells that are placed in a hypotonic solution? into

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what kind of solution causes crenation to happen to red blood cells? hypertonic

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what kind of solution cause chloroplasts to be pushed outward against the cell wall? hypotonic

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if a solution has more hydrogen ions than hydroxide ions, is it acidic or base? Acidic

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what is present in human blood that ensures blood ph is maintained at about 7.4? buffers

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what cellular components are common to prokaryotic and eukaryotic cells? DNA as genetic material, ribosomes, plasma membrane

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Ovarian follicle cells produce estrogen, which is a steroid. What organelle will be present in abundance so that the follicle cells might perform this

function? - endoplasmic reticulum. The cells in charge of these molecules move a lot of ser which allows them to produce this hormone. 

contact lens solution is described as a sterile, buffered, isotonic aqueous solution. explain the importance of the adjectives buffered and isotonic to the person buying the solution.- isotonic to not dry out or add too much moisture to the eye- water doesn't move. buffering agents stabilize pH level...