quiz laboratorio #3 pt.1

Question 1

objectives

Answer 1

• To learn about the Cell Theory
• To distinguish the difference between prokaryotic and eukaryotic cells
• To distinguish among eukaryotic cells, between plant and animal cells and to be able to identify the different structures of the cell and their function
• To understand how transport of substances across the cell, primarily through passive transport (diffusion and osmosis) by understanding these processes, tonicity and its importance for cell function
• To learn about and understand pH and buffers and their importance for cell function.

Question 2

The basic unit of life is the

Answer 2

cell

Question 3

We now know that all living organisms are composed of single cells (unicellular) or many cells (multicellular), that tissues are made up of cells, and that organs are made up of tissues, and organ systems of organs.

Question 4

thee cell theory states that:

Answer 4

1. All living organisms are composed of cells
2. That cells come only from other preexisting cells
3. That cells are the basic functional unit of all living organisms.

Question 5

Cells need energy to survive, whether it is in the form or chemical or solar energy, it takes in substances or takes out substances by means of

Answer 5

passive or active transport

Question 6

eukaryotic
Domain:

prokariotyc
Domain:

Answer 6

eukaryotic
(Domain Eukarya)

prokariotyc
(Domains Archaea or Bacteria)

Question 7

a phospholipids bilayer that sourrounds the cell and creates a boundary between the interior of the cell and its external environment.

regulates the movement of molecules into and out of the cytoplasm.

Answer 7

The nuclear envelope (plasma membrane)

Question 8

All cells also contain:

Answer 8

the hereditary material or DNA,
plasma membrane
cytoplasm

Question 9

carries the information that directs the cell activity and reproduction

Answer 9

the hereditary material or DNA,

Question 10

a semi fluid medium that contains water, salts, organic matter and other associated structures which fill the interior of the cell.

Answer 10

cytoplasm

Question 11

All living cells are classified as

Answer 11

either prokaryotic or eukaryotic.

Question 12

basic difference between prokaryotic and eukaryotic

Answer 12

prokaryotic don’t have nuclei, eukaryote do.

Question 13

Prokaryotes don’t have

Answer 13

the organelles found in eukaryotic

Question 14

Organelles are

Answer 14

small, membranous bodies, each with a specific structure and function.

Question 15

IN PROKARYOTES

The cytoplasm contains __________, which are…

_____________ that participate in photosynthesis

and innumerable _______

Prokaryotes also have a ____________, which contains a

Answer 15

ribosomes, small granules that coordinate the synthesis of proteins

thylakoids (only in cyanobacteria)

enzymes

nucleoid, chromosome composed largely of DNA with little protein.

Question 16

Eukaryotes have a membrane bound

The nucleus in a eukaryotic cell contains

The cytoplasm consists of a

Many organelles are membranous, such as the

Answer 16

nucleous, and organells.

nucleoplasm and the nucleolus

background fluid and the organelles.

nucleolus, endoplasmic reticulum, Golgi apparatus, vacuoles and vesicles, lysosomes, peroxisome, mitochondrion, and chloroplast.

Question 17

In this lab, we will study:
- the structure and function of prokaryotic and eukaryotic cells, the various organelles

-how the passage of water into or out of a cell depends on the difference in concentration of solutes (particles) between the cytoplasm and the surrounding medium or solution

• how the proper function of cells depends on the pH of their environment, amongst other factors.

-We will see how a buffer can maintain the pH within a narrow range and how buffers within cells can protect them against damaging pH changes.

Question 18

_____,______,________ are concepts that are central to cellular function

Answer 18

Difussion, osmosis, and tonicity

Question 19

Diffusion is defined as the movement

Answer 19

of molecules from a region of higher concentration to a region of lower concentration.

Question 20

Due to the differentially permeable plasma membrane surrounding a cell,

Answer 20

certain small molecules are able to cross it, going into and out of cells by simply by diffusion, which uses no energy.

Question 21

osmosis

Answer 21

diffusion of water across a differentially permeable membrane such as the plasma membrane of the cell.

Question 22

tonicity is

it controls

Answer 22

the relative concentration of solute , to solvent, inside and outside of the cell.

the concentration gradient of a molecule is controlled

Question 23

An isotonic solution has the…

When a cell is placed in an isotonic solution there is…

Answer 23

same concentration of solute, or water molecules, as the cell.

no net movement of water leaving or entering the cell and so the shape of the cell does not change.

Question 24

hypertonic solution has a

when a cell is placed in hypertonic solution, water will…

Answer 24

higher concentration of solute than the cell.

leave the cell, causing it to shrink.

Question 25

hypotonic solution, which has a... when cells are placed in hypotonic solutions water...

Answer 25

lower solute concentration than the cell, moves into the cell, causing it to swell and possibly burst.

Question 26

We will also examine diffusion and osmosis through a... For this purpose, we will use chicken eggs whose shells have been removed by treatment with acetic acid.

Answer 26

selectively permeable membrane

Question 27

Water, being a small molecule, can pass the cell membrane through both _______________, by slipping through the...

Answer 27

simple and facilitated diffusion phospholipid bilayer and by using aquaporins.

Question 28

the simplest type of diffusion occurs in example

Answer 28

the absence of a membrane smoke, potassium permanganate in corn syrup and water

Question 29

The rate of such diffusion will depend on many factors such as:

Answer 29

the physical properties of the medium in which it occurs (air, water, oil) the size of the particles which diffuse (smaller ones can move faster than the more sluggish big ones) the concentration of the diffusing particles.

Question 30

molecular weights increase... diffusion rates decrease exponentially as their

Answer 30

Diffusion rates decrease molecular weights increase.

Question 31

A solution of _______ is isotonic to red blood cells. A solution greater than 0.9% NaCl is _________ to red blood cells. In such a solution, the cells... A solution of less than 0.9% NaCl is _________ to red blood cells. In such a solution, the cells...

Answer 31

-0.9 % NaCI -hypertonic -shrivel up, a process called crenation -hypotonic - swell to bursting, a process called hemolysis

Question 32

pH is defined as the...

Answer 32

negative log of the H+ (ion) concentration -log [H+].

Question 33

The scale is divided into three areas: Each division either increases or decreases the pH of a substance...

Answer 33

Acid (reading below 7), Basic (reading above 7), or neutral (readings at 7). 10 times.

Question 34

Water has a pH of 7, but depending on the buffering capacity the water when mixed with air containing suspended materials will... _________ is an example of this.

Answer 34

either raise or lower the pH. Acid rain

Question 35

Different substances have different pH depending on

Answer 35

the relative concentration of hydrogen and hydroxide ions,

Question 36

Distilled water: Vinegar: Coca cola™: Milk: Tums™: Alka-seltzer™: Andrews™: Coffee: Baking soda: Ammonia:

Answer 36

-neutral -Acetic acid, acid -carbonic acid, a buffer, es acid -proteins, lactose, lipids; acid ph 6 -calcium carbonate, -baking soda y acid...neutral - sodium bicarbonate acid 6.6 -acid -base -strong base

Question 37

Buffers cause a solution to... and the degree of resistance is related to... , and depends upon the number of...

Answer 37

resist changes in pH (in other words they maintain the pH) the strength of the buffer buffering molecules present in a solution.

Question 38

Many buffers resist changes in pH by...

Answer 38

either absorbing H+ when an acid is introduced, or releasing H+ when a base is introduced.

Question 39

The majority of enzymes within the human body operate best at a pH of Physiological pH is maintained by a physiologic buffering system involving in aquatic systems the ________________ also plays an important role in maintaining environmental pH.

Answer 39

7.4 carbonate, phosphate, and protein. carbonate-bicarbonate system

Question 40

Now you can understand how the concept of pH is important in biology: All living organisms must maintain

Answer 40

living organisms are very sensitive to hydrogen ion concentrations (and hydroxide ion concentrations). the pH constant proper functioning.