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Flashcards in 2.1* Deck (183)
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Name all the parts of a animal cell.

Smooth and rough endoplasmic reticulum, lysosome, Ribosomes, Centrioles, Micro tubules, Nucleus, nucleolus, nuclear membrane, Mitochondria, Golgi apparatus, Plasma membrane.


Name the parts of a plant cell.

Nucleus, tonoplast, cell membrane (plasma), free ribosomes, cell wall (cellulose), SER, RER, chloroplast, mitochondrion, cytosine, Golgi Body, vacuole, nuclear envelope, amyloplast containing starch.


Describe the structure of the nucleus.

The nucleus is the largest organelle. When stained, it shows darkened patches known as chromatin. It is surrounded by a nuclear envelope. This is a structure made of two membranes with fluid between them. A lot of holes, called nuclear pores, go right through the envelope. These holes are large enough for relatively large molecules to pass through. There is dense, spherical structure, called the nucleolus, inside the nucleus.


What is the function of the nucleus?

The nucleus houses nearly all of the cells organic material. The chromatin consists of DNA and proteins. It has instructions for making proteins. Some of these proteins regulate the cells activities. When cells divide, chromatin condenses into visible chromosomes. The nucleolus makes RNA and ribosomes. These pass into the cytoplasm and proteins are assembled at them.


When a nucleus is stained what are the darkens patches known as?



What are the holes in the the envelope of a nucleolus called?

Nuclear pores.


What is the nucleolus?

A dark spherical structure inside the nucleus.


What does the chromatin consist of inside the nucleus?

DNA and proteins


What does the nucleolus make?

RNA and ribosomes


What is the structure of endoplasmic reticulum?

ER consists of a series of flattened, membrane-bound sacs called cisternae.
They are continuous with the outer nuclear membrane. Rough endoplasmic reticulum is studded with ribosomes. Smooth endoplasmic reticulum does not have ribosomes.


What is the function of rough endoplasmic reticulum?

Rough endoplasmic reticulum provides a large surface area for ribosomes which assemble amino acids into proteins. These proteins will actively pass through the membrane into cisternae and are actively transported to the Golgi apparatus. Some of these proteins may be secreted from the cell surface membrane.


What is the structure of a Golgi apparatus ?

A stack of membrane-bound, flattens sacs.
(It looks like a pile of pancakes)


What is the shape of mitochondria or a singular mitochondrion.

They may be spherical, rod shaped or branched. and are 2-5 um long.


What is chromatin?

Chromatin is genetic material, consisting of DNA wound around histone proteins.


What happens to the chromatin in the nucleus when the cell divides

The chromatin condenses and coils tightly into chromosomes. These make up nearly all the organisms genome.


How do prokaryotic cells divide?

Binary fission and not mitosis


Describe what happens before division in binary fission.

They do not have linear chromosomes, so could not carry out mitosis. However, before they divide, their DNA is copied so that each cell receives the large loop of DNA and smaller plasmids.


Do prokaryotes contain membrane-bound organelles?

Prokaryotes do not have any membrane bound organelles, but they do have organelles that are not covered by a membrane, such as ribosomes.


What are bacteria and micro-organisms?

Bacteria are micro-organisms because they are very small. They are also prokaryotes because of their cell structure. However, not all micro-organisms are prokaryotes. Yeast (which is a single celled fungus) and amoebae have eukaryotic cells.


Explain a viruses cells.

Viruses are microscopic but they do not have cells.


What is the job of the nuclear envelope?

It separates the contents of the nucleus with the rest of the cell.


How does mRNA leave the nucleus?

Through the pores.


What are 4 purposes of the nucleus?

To control the centre of the cell.
Stores the organisms genome.
Transmits genetic information.
Provides the instructions for protein synthesis.


What type of system is rough endoplasmic reticulum?

It is the Intracellular support system.


What is the structure of Smooth endoplasmic reticulum?

There is a system of membranes, containing fluid-filled cavities (cisternae) that are continuous with the nuclear membrane.
There are no ribosomes on its surface.


What is the function of smooth endoplasmic reticulum?

SER contains enzymes that catalyse reactions involved with lipid metabolism, such as;
synthesis of cholesterol
synthesis of lipids/phospholipids needed by the cell.
synthesis of steroid hormones.
It is involved with absorption, synthesis and transport of lipids (from the gut).


What brings materials to the Golgi apparatus?



How are proteins modified in the Golgi apparatus.

Adding sugar molecules to make glycoproteins.
Adding lipid ,molecules to make lipoproteins.
Being folded into their 3D shape.


In the Golgi apparatus what happens after the protein is packaged into a vessel?

It is stored in a cell or
Moved to the plasma membrane, either to be incorporated into the plasma membrane, or exported outside the cell.


What is the structure of a mitochondrion?

They are surrounded by two membranes with a fluid filed space between them. the inner membrane is highly folded into a cristae.
The inner part of a mitochondrion is a fluid filled matrix.