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MCC Biology 1000 Professor K. Sak
Biology 1000 Ch 4 Cell Structure & Function
34
Biology
Undergraduate 1
09/11/2016

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Cards

Term
1.Why are cells small?

Definition
The surface‑area‑to‑volume ratio requires that cells be small. 
Cells need a large surface area of cell membrane to adequately exchange
materials – everything need to stay alive. 
*Large cells - surface area relative to volume decreases
*Small cells – larger surface area to volume ratio is advantageous for exchanging molecules
Term
2A. What are the two types of cells?  
Definition

1. Prokaryotic Cells Lack a membrane-bound nucleus and complex organelles making them structurally smaller and simpler than eukaryotic cells

* Prokaryotic cells lack a nucleus and other organelles.

2. Eukaryotic Cells - cells have a nucleus amd other organelles. 

Cells contain:

1. Membrane-bound nucleus that houses DNA

2. Specialized organelles in the cytopla

3. Plasma membrane

•Much larger than prokaryotic cells



Term

2B. What characteristics does a prokaryotic cell have? 

Definition

The Structure of Prokaryotes 

*****Extremely small: 1–1.5 μm wide and 2–6 μm long

•Occur in three basic shapes:
*Spherical coccus,
 * Rod-shaped bacillus,

 §Spiral spirillum(if rigid) or spirochete(if flexible)


 

Term
2C. What are the similarities in cells? 
Definition
Both prokaryotes and eukaryotes cells have:
1.  Both organisms are composed of cells, the basic unit of life, 
2. Both  have DNA as their genetic material.
3. Cytoplasms
4. Cell Membrane
5. Ribosomes
6. Some have flagella
Term

2D. What are the cell differences?

The biggest difference between prokaryotes and eukaryotes is that eukaryotes have a nucleus. Prokaryotes are smaller in size as well. The eukaryotes cells also have other membrane structures called organelles.The DNA of eukaryotes is much more complex and therefore much more extnsive than the DNA of prokaryotes. 

Definition

Prokaryotes                               Eukaryotes

1. No nucleus                                    1. Cells have a nucleus

2. Small and simple                           2. Have organelles

3. No organelles                                3. Can be unicellular or multicellular

4. Are very adundant                         4. Have a cytoskeleton

5. Cells have a cell wall                     5. Some have cilia

6. Were the first cells                        6. Includes everything that's not bacteria 

7. Live a wide variety of environments

8. All are bacteria

 

 

Term
3. Know the names and basic function of each of the organelles found in eukaryotic cells.

*****Functions on a different notecard***************
Definition
Two Types of Eukaryotic Cells Organelles
1. Endomembrane system
•Organelles that communicate with one another
–Via membrane channels
–Via small vesicles
2. Energy related organelles
Mitochondria and chloroplasts

Independent and self-sufficient 

Term
4. Be able to identify them on a drawing/picture.
Definition
Look at PowerPoints.
Term
5. What are the differences between animal and plant cells?
Definition

The differences between the two types of cells can be seen with a light microscope.Below is a list of the major differences:

  
ANIMAL CELLS PLANT CELLS
Does not have a cell wall,  irregular in shape Has a cell wall, regular in shape
No chloroplast present Chloroplast present
Small temporary vacuoles or no vacuole Large vacuoles located in the centre of the cell
Starch grains not present Starch grains present
The nucleus is usually located centrally Due to the central location of the vacuole, the nucleus of the cell may be located at the edge of the cell
 
 

 

 
 
Term
6. What is the endosymbiont theory?
Definition

This theory suggests that mitochondria and plastids in eukaryotic cells were once independent prokaryotic cells. Basically, this means that once upon a time, there were three prokaryotic cells: one that was capable of aerobic respiration and converting energy, one that was capable of photosynthesis and one that was incapable of doing either of these processes. The lazy cell that was incapable of doing respiration and photosynthesis engulfed - or ate - the other cells.

Term

Surface to Volume Ratio

 

What is the total surface area formula? 

Definition

Total surface area:

(Height x width x length x number of cubes)

Term

Surface to Volume Ratio

 

What is the total volume area formula? 

 

 

Definition

Total volume area:

(height x width x length x number of cubes). 

Term

Surface to Volume Ratio

 

What is the total volume area formula? 

Definition

Surface area:

Volume per cube (surface/volume). 

Term
2E. What characteristics does a eukaryotic cell have?
Definition

2. Eukaryotic Cells: Organelles

Eukaryotic cells are compartmentalized
*They contain small structures called organelles which are isolated from each other
* Each organelle performs a specific function
•Organelles are placed in one of two types
*Endomembrane system
•Organelles that communicate with one another
–Via membrane channels
–Via small vesicles
Energy related organelles
Mitochondria and chloroplasts

                      •Independent and self-sufficient

Term

Define Organelle. 

Definition
An organelle is a subcellular membrance-bounded structure that performs specific(s) for the cell. 
Term
Define unicellular. 
Definition
Unicellular is living organisms built of a single cell. 
Term
Define multicellular. 
Definition
Living organisms constructed from large numbers of highly interdependent cell forms of life. 
Term

TYPICAL ANIMAL CELL

Definition
[image]
Term
Plant Cell
Definition
[image]
Term
The Nucleus and Ribosomes
Definition
•The Nucleus
* Command center of cell, usually near center
* Separated from cytoplasm by nuclear envelope
•Consists of double layer of membrane
Nuclear poresselectively permit exchange between nucleoplasm & cytoplasm
* Contains chromatin
•Chromatin is the DNA uncondensed and various proteins
•Chromatin condenses to form chromosomes
–Chromosomes are formed during cell division
* Dark nucleolus composed of ribosomal RNA (rRNA)

•Produces subunits of ribosomes – another organelle

Term

Ribosomes

Definition
Are the site of protein synthesis (making) in the cell
•Composed of ribosomal RNA (rRNA)
* Consists of a large subunit and a small

    subunit that are made in the nucleolus

May be located:
* On the endoplasmic reticulum – another organelle

 

* Free in the cytoplasm, either singly or in groups, called polyribosomes
Term

The Endomembrane System

Definition
•Series of intracellular membranes that create specialized compartments in the cell in which specific types of chemical reactions occur
•Consists of:
- Nuclear envelope
- Membranes of Endoplasmic Reticulum
- Golgi apparatus
* Vesicles

•Transport materials between organelles of system

Term

Endoplasmic Reticulum

Definition
A system of  membrane channels and saccules (flattened vesicles) continuous with the outer membrane of the nuclear envelope 
 
Two types: 
1. Rough Endoplasmic Reticulum
2. Smooth Endoplasmic Reticulum
Term
Rough Endoplasmic Reticulum
Definition
- “Studded” with ribosomes
- Functions in protein synthesis by modifying and processing the proteins made by the ribosome  by adding sugars
- Results in glycoproteins

 

- Forms transport vesicles that carry the glycoproteins to another organelle
Term
Smooth Endoplasmic Reticulum
Definition
-Continuous with the nuclear envelope and the rough endoplasmic reticulum
- No ribosomes
- Synthesis of lipids
- Site of various synthesis for other materials, detoxification of drugs, and storage

- Forms transport vesiclesthat carry the products  to another organelle

Term

The Golgi Apparatus

Definition
- Consists of flattened, curved saccules that resembles stack of hollow pancakes
- Further modifies proteins and lipids that are received in vesicles from either of the ERs
- After modification, the proteins and lipids are prepared for “shipment” and repackaged into vesicles
- Some vesicles will stay within cell and be used by the cell

         - Other vesicles will be exported or secreted from the cell for use by other cells

Term
Lysosomes
Definition
Membrane-bound vesicles (not found in plants)
§Produced by the Golgi apparatus
§Contain powerful digestive enzymes and are highly acidic
Digestion of large molecules

Recycling of cellular resources 

Term

Endomembrane System Summary

Definition
Proteins produced in rough ER and lipids from smooth ER are carried in vesicles to the Golgi apparatus
The Golgi apparatus modifies these products and then sorts and packages them into vesicles that go to various cell destinations
Secretory vesicles carry products to the membrane where the product is released

 

Lysosomes fuse with damaged organelles, foreign particles or incoming vesicles and digest macromolecules
Term
Energy-Related Organelles
Definition
Chloroplasts
§Have a double membrane
§Inner membrane is infolded
Forms disc-like thylakoids, which are stacked to form grana (looks like stacks of pancakes)
Suspended in semi-fluid stroma
§Green due to chlorophyll
Green photosynthetic pigment
Found ONLY in inner membranes of chloroplast

§Chloroplasts contain ribosomes and their own DNA separate from the DNA in the nucleus 

 
Term
Chloroplasts
Definition
Captures light energy to drive cellular processes that allow organisms with chloroplasts to make carbohydrates
Photosynthesis
§Synthesizes carbohydrates from CO2 & H2O
§Makes own food

 

§Only plants, algae, and certain bacteria are capable of conducting photosynthesis 
Term
Mitochondria
Definition
Smaller than chloroplast
Contain ribosomes and and their own DNA separate from the DNA in the nucleus  
Surrounded by a double membrane
§Inner membrane surrounds the matrix(center) and is convoluted (folds) to form cristae
§Matrix – Inner semifluid containing enzymes that break down carbohydrates to release energy
Involved in the process of cellular respiration
Produce most of ATP utilized by the cell
§ATP = adenosine triphosphate
§The energy molecule of organisms
Term
Centrioles
Definition
Short, hollow cylinders
§Composed of 27 microtubules
One pair per animal cell
§Located in centrosome (area) of animal cells
§Oriented at right angles to each other
§Important during cell reproduction

 

May be involved in the synthesis of cilia and flagella
Term

Cilia and Flagella

Definition
Hair-like extensions of the plasma membrane that project from cell surface that aid in cell movement
§This is very different from prokaryote flagella
In eukaryotes, cilia are much shorter than flagella
§Cilia move in coordinated waves like oars
§Flagella move like a propeller or cork screw

 

The only animal cell with a flagellum is sperm
Term
Prokaryotic Cells P1
Definition

Cell Envelope is made up of:

*Plasma membrane- lipid bilayer with

     embedded and proteins

Cell wall - maintains the shape of the cell
Glycocalyx  or Capsule - layer of polysaccharides (sugars) on the outside of the cell wall which is well organized and resistant to removal
•Prevents drying out
•Helps bacteria attach to almost

   any surface (including you)

•Helps disease causing bacteria “bypass” your immune system. 
 
Term
Prokaryotic Cells P2
Definition
Cytoplasm is a semifluid solution within the plasma membrane and contains water, inorganic and organic molecules, and enzymes that carry out the cell functions
Ribosomeshelps to make the proteins the cell needs
Nucleoid is a region that contains the single, circular DNA molecule
Plasmids are small accessory (extrachromosomal) rings of DNA
Appendages
*Flagella – provide motility
*Fimbriae – small, bristle-like fibers that sprout from the cell surface

           *Conjugation pili– rigid tubular structures used to pass DNA from cell to cell

 

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