USABO and AP Biology Unit 2 or Chapters 6 and 7 Flashcards Extremely Detailed

Contains terms from both, (Both) means that this flashcard is important for both things, and (USABO only) means just for USABO it is not necessary for AP Bio. Chapter Marks. Chapter 6: (1-243).

When was microscopy invented? (Both)

1590s and refined in the 1600s

Who discovered living cells (USABO only)

Anton van Leeuwenhoek

Definition of Light Microscope and it’s abbreviation (Both)

LM and they are microscopes where visible light is passed through a specimen and then through glass lenses

What three important parameters exist for microscopes (Both)

Magnification, resolution, and contrast

What is the smallest size a LM can see? (USABO only)

200 nanometers

What type of microscope parameter stops LMs from viewing things as small as electron microscopes? (Both)

Resolution

How does an electron microscope work and what is it’s abbreviation? (Both)

Uses beams of electrons through a specimen, EM

Why are electron microscopes better at viewing smaller objects? (Both)

They have shorter wavelengths then light

Use of Scanning Electron Microscopes and abbreviation (Both)

Useful for detailed topography of an organism, SEM

How do SEM’s work (Both)

The organism is plated in a thin film of gold, which excites the electrons on the gold, creating a 3D electrical image on the screen of a surface

How do Transmission Electron Microscopes work and what’s their abbreviation?

An electron beam is aimed through a thin section of a specimen, which has been stained by heavy metals that attach to certain structures in the cell, enhancing the electron density and making them more visible. (Like dying a cell with heavy metals). Abbreviation is TEM

What are the pros of light microscopy, 2 main ones (Both)

1. Light microscopy is easier to use, less expensive, and more common

2. Light microscopy can be used to study living cells

What is/are the con(s) of light microscopy? (Both)

It is harder or impossible to see subcellular structures

Pros of electron microscopes (Both)

1. Can see 100 times more zoomed in then a light microscope

Cons of EM (Both)

The preparations used to prepare the specimen usually kill it, so you can’t view live cells

Every type of light microscopy (USABO only, super important please memorize if you’re in USABO)

1. Brightfield

2. Phase contrast

3. Different Interference Contrast (Nomarski)

4. Fluorescence

5. Confocal

6. Deconvolution

7. Super resolution

8. Cryo-electron microscopy

How does brightfield light microscopy work? (USABO only)

Light passes through the specimen, and you get contrast without dyes, but the specimen has to be killed or preserved

How does phase contrast light microscopy work? (USABO only)

Variations in the density are amplified to enhance contrast without dyes, and is useful for examining living cells

How does difference interference contrast light microscopy work? (USABO only)

Optical illusions are used to exaggerate density, resulting to 3D like images, and can be used on living organisms

How does fluorescence light microscopy work? (USABO only)

Locations of specific molecules are revealed by labeling molecules with dyes and UV light, but the final image is blurry but magnified much higher. You have to kill/preserve the cell

How does confocal microscopy work? (USABO only)

A laser which is used to create a single plane of microscopy in fluorescence, a 3D image is now created by adding different planes. Usually still blurry and the specimen has to die

How does deconvolution microscopy work? (USABO only)

A deconvolution software that removes and reassigns light, creating a sharper image. Basically uses fluorescence microscopy and focuses it in. Increases resolution

How does super-resolution microscopy work? (USABO only)

Uses individual UV light pieces to excite fluorescent molecules. The positions are rounded and the changing images create a more resolved image, which can be increadly small, up to 10-20 nm across.

What temperature are the specimens in cryo electron microscopy frozen at? (USABO only)

At least -160 degrees celsius

Use and how you use cryo-electron microscopy? (USABO only)

It is used to view detailed protein structures and makes an image of tiny electron graphs

Definition of Cell Fractionation (Both)

A technique for studying cell structure by taking apart cells and separating major organelles from each other

Steps of Cell Fractionation (Both)

Homogenization, centrifugation, differential centrifugation

Definition of centrifugation (Both)

A high speed rotational force that pulls things away from each other, essentially separating them

Definition of homogenization in the cell Fractionation context (Both)

Mixing up stuff in a blender and making them into a homogenous mixture

What is the following thing called after homogenization? (Both)

Homogenate

Definition of Differential Centrifugation and why we do it(both)

When substances are put into a centrifuge and it spins at different speeds. When a centrifuge works, it’s forces are measured in gs, so a different type of cell organelle or part appears at the bottom of the tube for each g. For example 1000gs shows nuclei and cellular debris.

Two types of cells (Both)

Prokaryotic and Eukaryotic

Similar features for both types of cells (Both)

1. Bound by a plasma or cell membrane

2. They have cytosol

3. All cells have DNA

4. All cells have ribosomes

Definition of cytosol (Both)

A jelly like fluid where all cells are suspended in

Differences between eukaryotes and prokaryotes (Both)

1. Eukaryotic cells have membrane bound organelles, meaning each organelle has a membrane that separates it

2. Prokaryotic cells don’t have membrane bound organelles

3. Eukaryotic chromosomes are stored in the nucleus

4. Prokaryotic cells don’t have a nucleus, they have a nucleoid which is a concentrated region of DNA in a membrane

5. Eukaryotes are generally much larger than prokaryotes

Definition of cytoplasm, and which cell has it?

the area between the nucleus and the plasma membrane in a cell, and both have it. For prokaryotes it’s the entire cell

Fill in the blank, for each square micrometer of a membrane, only a __________________________________________________________ (Both)

limited amount of a particular substance can cross per second

The ratio between what two mathematical terms is essential to cell biology? (Both)

Ratio of surface area to volume

What mathematical law support this claim and state the law you can state a close version as long as you understand it? There are two parts to this law (USABO only)

1. Area is proportional to a linear dimension squared whereas volume is proportional to the linear dimension cubed

2. As an object increases in size, the ratio of it’s surface area decreases proportionately

Square Cube Law

How does the Square Cube Law affect life? (three things) (Both)

1. Smaller cells have larger surface area

2. Usually the larger a cell gets the longer it gets with it

3. Limits cell size, and supports why large organisms usually don’t have larger cells, just more similar sized cells

Main Purpose of the Nucleus (Both)

Contains most of the genes in the eukaryotic cell

What other organelles contain DNA in eukaryotes? (Both)

Mitochondria and Chloroplasts

Role of the nuclear envelope (Both)

Encloses the Nucleus, separating it’s contents from the cytoplasm

What type of membrane encloses the Nucleus? (Both)

Double membrane

How big is the space between the double membrane in the nucleus? (USABO only)

20nm - 40nm

What perforates the nuclear envelope? (Both)

Pores

Definition of a pore complex (Both)

An intricate protein structure that lines each pore and plays an important role in the cell by regulating enter and exit of proteins and RNA

Where is the Nuclear Lamina (Both)

Lines the nuclear envelope everywhere except the pore

What is the Nuclear Lamina made of and what does it do? (Both)

It is made of proteins and it maintains the Nuclear lining

Nuclear Matrix what is it tell everything about it (USABO only)

Nuclear matrix is a concept that has evidence from some scientists that may help the lamina and envelope function effectively together

Definition of a Chromosome (Both)

Discrete units that carry genetic information shaped kind of like an X

What protein does DNA wrap around in chromosomes (Both)

Histones

Definition of Chromatin (Both)

The complex of DNA and Proteins

Can you view cells dividing in chromosomes? Y or N (Both)

Yes

What is the Nucleolus (Both)

A dense round structure inside the nucleus of a Eukaryotic cell that builds and assembles ribosomes

How does the nucleolus look like? (Both)

A mass of densely stained fibers and granules

What is assembled in the nucleolus? (Both)

Ribosomal RNA and ribosome subunits

True or False, there can be only one nucleolus? (Both)

False there can be multiple nucleoli

What factors affect the amount of nucleoli in a cell? (Both)

Cell species and reproductive cycle

What theorized thing could nucleoli control? (USABO only)

Cell division and lifespan

What is a ribosome? (Both)

Complexes made of complex RNA and proteins which are the cellular components that carry out protein synthesis

True or false ribosomes are not organelles (Both)

True

What factors can effect the amount of ribosomes in a cell? (Both)

Higher rates of protein synthesis

What are the two types of ribosomes? (Both)

Free and Bound ribosomes

Where do free ribosomes “live”? (Both)

In the cytosol

Where do bound ribosomes “live”? (Both)

Endoplasmic Reticulum

How are these ribosomes different from each other purely in structure? (Both)

They’re not different they’re all structurally identical

What different functions do bound ribosomes carry out? (Both)

make proteins that are supposed to be inserted into the cell membrane

What is the endomembrane system? (Both)

Network of organelles that package, process, and transfer proteins

What organelles are in the endomembrane system? (Both)

Endoplasmic reticulum, golgi apparatus, lysosomes, vesicles, vacuoles, and the plasma membrane

What 4 other functions does the endomembrane system carry out? (Both)

Synthesis of proteins, transport of proteins into membranes and organelles out the cell, metabolism, movement of lipids, and detoxification of poisons

How are these organelles related? (Both)

They are in direct contact with each other or they transfer vesicles

What is a vesicle? (Both)

A tiny organelle sac made of membrane

What is the endoplasmic reticulum made of? (Both)

Cisternae

What are cisternae? (Both)

Sacs that make up the endoplasmic reticulum

What is the ER Lumen? (Both)

The continuous internal space in the ER covered by the ER membrane

What space does the ER membrane share its contiguous membrane with? (Both)

Nuclear Envelope

What are the two regions of the ER? (Both)

Rough and Smooth ER

What are the functions of the smooth ER? (USABO only) (AP BIO recommended)

1. Synthesis of lipids

2. Metabolism of carbohydrates

3. Detoxification of Drugs and Poisons

4. Storage of calcium ions

What types of cells are rich in the smooth ER? (Both)

Cells that specialize in synthesizing lipids and sex hormones (steroids)

How does detoxification occur in the smooth ER? (USABO only)

Detoxification involves adding hydroxide to drugs to make them polar so they can be diluted safely with water

How do barbiturates, drugs, and alcohols affect the ER? (Both)

They make it bigger

What are the functions of the Rough ER? (Both)

Produce proteins, produces membrane proteins and produces phospholipids

What type of proteins are most secretatory proteins? (Both)

Glycoproteins

Definition of a glycoprotein (Both)

A protein with a carbohydrate covalently bonded to them

Why is the Rough ER rough? (Both)

Because of the many ribosomes dotted all over it

Where are the polypeptide chains from ribosomes thread to? (Both)

The ER Lumen

Where do secretory proteins go after they leave the ER Lumen? (Both)

The ER Membrane

Where do secretory proteins go after the ER Lumen and what are they wrapped in? (Both)

They go to the transitional ER and are wrapped in vesicles

What real life building resembles the Golgi Apparatus? (Both)

The warehouse

What does the Golgi Apparatus do? (Both)

It modifies, stores, and packages products of the ER, and sometimes even manufactures its own products

What type of cells have large Golgi? (Both)

Cells that are good at secretion

What is the GA made of? (Both)

Cisternae

Definition of a Cisternae (Both)

A group of associated flattened membranous sacs

What separates each cisterna from the cytosol? (Both)

The membrane

What are the two distinct sides of the Golgi Stack? (Both)

The cis and trans sides

How do the cis and trans side of the ER differ? (Both)

They differ in thickness and molecular composition

Where is the cis side of the Golgi Apparatus located? (Both)

Near the ER

What moves proteins from the ER to the cis side? (Both)

Vesicles

What does the trans side do? (Both)

It creates vesicles