Chapter 6 (pt1) - Cellular Anatomy Flashcards
simplest biological organization that’s alive?
Cell
what’s the size of cells in comparision to other biological entities?
they are in the near middle area
what’s the size of the smallest biological being? what is the name of it?
smallest biological beings are bacteria at 100nm
are proteins and lipids and part of biological systems alive?
no, they are just parts of biological system
how do we see small biological molecules like proteins and ribosomes?
through electron microscopy
are there any other types of microscopy?
Yes, light microscopy
briefly explain light microscopy
Light microscopy is a technology used to study and see molecules that are too tiny to be seen under normal vision.
There are different levels of resolution and different types of filters from which we can observe the molecules
briefly describe electron microscopy
electron microscopy is similar to light microscopy except that the technology uses electron beams to see the molecules.
how is electron microscopy different than light microscopy?
electron microscopy uses electron beams to shine light on molecules
light microscopy uses a beam of light to magnify the molecules
electon microscopy provides a much better magnified view of the molecules than the light microscopy
electron microscopy provides better resolution as well
what are the two types of electron microscopy? briefly describe the difference between their functions
Scanning electron microscopes
and
Transmission electron microscopes
SEMs focus the electron on the SURFACE of molecules to achieve a 3D look
TEMs focus the electron THROUGH the molecules to get a indepth view of them
what is another method scientists use to study the cells closely other than electron/light microscopy? explain the concept of the method briefly
Cell fractionation;
it involves fractioning or taking the contents of the cells apart (basically breaking the cell down into smaller components to study the smaller components)
how does the process of cell fractionation work?
To seperate the chosen cells to small components, homogenization is performed on them which involves putting them into blenders
Then depending on which subset or components of cell is wanting to be studied, it’s blended at different speeds which is known as Centrifugation. So if you want ribosomes to be studied, they have to be centrifuged or blended at a faster and longer speed/duration than a cell membrane
(mnemonic) homogenization = homogenous = all same = being mushed tog
what are the two types of cells?
eukaryotes and prokaryotes
what are some components/characteristics both types of cells shares
both have a plasma membrane
both cells are submerged with a fluid called cytosol inside it
both contain genetic information written in chromosomes
both have protein making components called ribosomes
is cytoplasm and cytosol the same thing
Yes.
what’s the main difference between eukaryotes and prokaryotes?
Prokaryotes’ DNAs are not enclosed by any membranes and is located in nucleoid
They are also very small in size compared to eukaryotes
what characteristics basically define eukaryotic cells?
- the nucleus is bound by its own membrane* (unique)*
- some of the smaller components alsohave their own membranes (endomembrane)
- their components are more in quantity
how are plant cells different than animal cells?
-Plant cells contain chloroplasts
-It has a cell wall made up of cellulose instead of phospholipids
-the central vacuoles are air/water filled
In Eukaryotic cells, Is all of the DNA contained in the nucleus?
NO
some is in mitochondria/chloroplasts
what is the structure of nucleus like?
- the nucleus is enclosed by the border of **nuclear envelope **
- not only does the nuclear envelope help define the shape but the nuclear lamina, a protein structure, also maintains the nucleus’ shape
- there are two membranes of the nucleus : inner and outer
- the nuclear membrane is made up of a lipid bilayer
- the permeability of molecules into nucleas is maintained by nucleus pores
nuclear lamina - protein structure
does mitochondria have a double membrane?
YES
does chloroplast have a double membrane?
YES
where is the DNA located in the nucleus?
around the center where th DNA is actually wrapped around proteins to make a complex structure called the Chromatin
BASICALLY : DNA + PROTEINS = CHROMATIN
where is rRNA or ribosomal RNA made?
in the nucleolus of nucleus
what is the central dogma of DNA and RNA?
DNA is knowledge center -> DNA makes RNA -> RNA is messenger -> RNA gives knowledge to ribosomes -> Ribosome makes proteins using DNA’s knowlegde
What happens to the chromatin when the cell is about to divide?
It condenses, or gets packed together very tightly. This condensed state becomes chromosomes where each DNA molecule is packed around proteins
Chromatin - a bunch of DNA strands wrapped around proteins
explain rRNA
rRNA = ribosomal RNA
they are a component of ribsomes that carry the knowledge of protein synthesis.
explain the function of ribosomes and its relationship with rRNA
Ribosomes are an organelle that make proteins in the cell
They compose of two subparts - rRNA and protein
explain the structure of ribosomes
the ribosome is composed of two units namely Large subunit and Small subunit.
The Large subunit contains 40-60 different proteins + rRNA
The Small subunit contains 30-50 different proteins + rRNA
where are ribosomes generally located?
They are located in two locations:
1. The ribosomes that just float around in** cytoplasm** are called free ribosomes
2. The ribosomes attached to Endoplasmic Reticulum are called bound ribosomes
what do free ribosomes do?
they make soluble proteins
are ribosomes attached to rough Er or smooth Er?
Ribosomes are attached to rough ER
(that’s why they have a rough texture)
does the entire Endoplasmic Reticulum have one homogenous function?
No, Endoplasmic Reticulum is an inner membrane of the cell but they are divided into two parts (Rough ER and Smooth ER) of it have different functions
where is the Endoplasmic Reticulum located?
It is continuous from the nuclear envelope, meaning its start forms from the end of the nuclear envelope
explain the function of Smooth ER
They make lipids in the cell
they metabolize the carbohydrates
detoxify drugs + poision
storage compartments - stores calcium ion
explain the function of rough ER?
the ribosomes on it produce glycoproteins (carb+protein)
they aid in molecule’s transportation through transport vesicles
also makes membrane proteins (proteins whose functions exist in other membranes)
how does a rough ER look like? What are the spaces in rough ER called?
The Rough ER’s membrane has folds and twists that create spaces between each folds called ER lumen
Is the ER Lumen and ER cisternae the same thing?
Yes
what are the functions of the Golgi Apparatus?
the Golgi Apparatus recieves transport vesicles FROM THE ER and modifies its contents as they enter from cis face side to the trans face side
It also sorts and packages the vesicles with molecules and transports it
what is the location of Golgi Apparatus?
The Golgi Apparatus is located near the ER
what does the golgi apparatus look like?
They are basically flattened membrane sacs with folds, the space between folds are called cisternae.
Cis face is the smaller end of the organelle
Trans face is the larger and bigger end of the organelle
what’s the relationship like between Golgi Apparatus and ER?
ER makes membranes and transports the molecules into vesicles and the GA modifies them/synthesizes molecules for vesicles and sends them out in the cell
what are the functions of lysosomes?
Lysosomes are a set of digestive enzymes and contain acid that is used to break down macromolecules
what do lysosomes look like?
They are membranous vesicles with lysosome enzymes inside
How do lysosomes break down and digest the molecules?
There are two methods lysosomes breaks down something
1. Phagocytosis : for intracellular digestion
2. Autophagy : for recycling cell materials
How does phagocytosis work?
A food vacuole (pouch with food molecule) enters the cell which is then fused by the lysosomes to digest it down and release into the cell
How does Autophagy work?
When cellular components are not needed anymore, the lysosome will fuse with the components and its enzymes will break down the components.
In other words, the lysosomes COMES TO THE molecule instead of the other way around
relationship between vesicle and vacuole?
Vesicle is just a small version of a Vacuole but both are membrane bound molecule that transports molecules
What is reverse phagocytosis?
outward movements of molecules (from cell to outside cell)
What are the three types of vacuoles?
- Food : carry food molecules into cell for phagocytosis
- Contractile : pump out excess water from cells
- Central : storage of water + compounds in plant cells
What is the function of central vacuole in plants?
The central vacuole helps increase volume of cells without adding weight because it’s filled with air
Sometimes it’s used to store water/compounds
which components of the cell are membrane bound?
Mitochondria/Chloroplasts
Peroxisomes
Nucleus
What’s the function of mitochondria?
it is to synthesize ATP and perform cellular respiration
What does it mean when a cell’s component is membrane bound?
The component’s subparts are surrounded by a membrane seperating it from others
What is the function of chloroplasts?
photosynthesis is performed in these regions
what is the function of peroxisomes?
Peroxisomes are oxidative organelles that catalyze oxidative reactions ( they use oxygen ) to carry out different metabolic reactions
What’s so unique about chloroplasts and mitochondria in compare to other cell components?
Chloroplasts and Mitochondria are both surrounded by a double membrane,
they have their own unique ribosomes and DNA (which are not found in the DNA of the nucleus)
What conlcusion/theory did the unique properties of chloroplasts/mitochondria lead to?
it lead to the theory of Endosymbiont Theory where it’s alleged that mitochondria and chloroplasts were their own seperate organisms but were engulfed by a larger cell which then created eukaryotic cells
What is the structure of mitochondria like?
It has two membranes :
The outer membrane is smooth and seperates the inner membrane from the cytosol
The inner membrane is folded into** folds called cristae,** the space inside the folds is divided by two regions called the intermembrane space. and **mitochondrial matrix **
What is the structure of chloroplasts like?
the chloroplasts also have two membranes. Inside the inner membrane, there are two components - sacs each individually called thylakoids that are known as granum as a whole. These sacs are dispered in stroma (a fluid)
Do peroxisomes also have a double membrane?
No, they have a single membrane in which fluid fills the inside and it contains enzymes
