Lesson 1- Cytology (intro to cells) Flashcards
What is Cytology?
Cytology is the study of cells
What is a cell? And what are their purpose?
The basic unit of all living things.
-cells make up who we are on the outside and the inside
- cells die and I replaced on a regular basis
- Cells are like tiny living building blocks
- responsible for carrying on all life processes
- body consists of trillions of cells which very in shape size and purpose
- cells are about 60% water which is why water is so important for life
- all the cells in the body are constantly bathed in salt water solution called interstitial fluid which is derived from the blood.
- all exchanges between cells and blood are made through this fluid
- it can be compared to a big city with dozens of power stations and transportation systems. It imports raw materials, manufactured goods and operates as a garbage disposal system
- they have the ability to grow and reproduce
- cells have the ability to respond and adapt to changes in the environment
List the different parts of the cell (11)
- The cell membrane
- Cytoplasm/Protoplasm
- Ribosomes
- Endoplasmic reticulum (ER)
- Mitochondria
- Lysosomes
- Golgi apparatus
- Centrioles
- Nucleus
- Chromosomes
- Genes
Describe the cell membrane and its function
The cell membrane surrounds the cell and keeps the cell shape. This is the outer wall of the cell which supports and protects the cell structure. It encloses the proto Plazum. It is composed of a double layer of fat surrounded by two layers of protein. It is very flexible to allow for growth. Permits soluble substances to enter and leave the cell. It also serves as a semi permeable passageway for oxygen, carbon dioxide and water to pass in either direction fairly easily.
What are receptors and where are they located?
- Receptors are located on the cell membrane – these are known as receptor sites. -Receptors act like a lock and key for substances to enter the cell membrane. -Receptors are the communication system between different cells, Tissues, organs and parts of the body.
- Receptors also receive messages from whore moans and other chemical messengers made by other cells. Hormones are chemical messengers.
What is the cytoplasm?
- The cytoplasm is just after the membrane and the site of most activity also referred to as the factory area of the cells.
-  Cytoplasm is part of the Protoplasm (fluid that supports inner structure of the cells)
- Protoplasm includes the nucleus where cytoplasm does not.
- cytoplasm consists of organelles except the nucleus. The Protoplasm consists of the nucleus, cytoplasm and plasma membrane.
- It is a slightly granular fluid that acts as a support for all the structures within the cell. It is necessary for growth, reproduction and self repair.
What is the Endoplasmic reticulum (ER)?
-Looks like a maze – the pathways in highways of the city
-It’s the little net work within the cytoplasm
-Consists of clear tubular structures which serve as passageways for cellular material. For example amino acids which are transformed into protein
-This network of material forms little canals with the cytoplasm that allows substances in other organelles to move around
-Think of the ER as blood vessels within the body. The ER can have two appearances one rough and one smooth. The rough ER has ribosomes attached to it and the smooth does not.
-rough ER produces phospholipids and proteins that are either packaged or secreted from the cell.
-The inner surface of ER is lined with ribosomes. They are called: rough ER whereas the smooth ER does not have ribosomes
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What are ribosomes
- Ribosomes are small granules of protein located along the inner surface of the endoplasmic reticulum, nucleoli, and in the cytosol
- They “read” coded genetic messages [RNA] and assemble amino acids into proteins specified by the code. Protein equals a chain of amino acids.
- They contain a large amount of extremely important proteins called RNA [Ribo nucleic acid]
- River zones are actual site of protein synthesis in the cell. Some of the newly constructed protein molecules are passed out of the cell to act in other parts of the body
- Ribosomes can float freely within the cytoplasm or attached to either the ER or the nuclear membrane
What are mitochondria
- produces energy – are the cells lungs and digestive system, converting oxygen and nutrients so they can be used as energy by the cell
- The powerhouse of the cell. It has a catabolic function meaning it takes complex substances and breaks them down into simpler forms
- it breaks down glucids (sugar) and lipids (fats) and releases them into the cell. The broken down glue sids and lipids serve as energy for the cell.
- Breaks down nutrients fats and carbs and turns them into ATP. As the foods are broken down energy is released. Much of this energy escapes as heat but some are captured and used to form ATP molecules [adenosine triphosphate]
- ATP provides the energy for all cellular work and every cell requires a constant supply of ATP. Mitochondria is referred to as the powerhouse of the cells because it supplies most of the ATP. Anything the cells want to do or accomplish will rely on ATP
- If mitochondria doesn’t have enough energy it slows down function and doesn’t produce enough energy which is aging.
What are lysosomes
-They are concerned with intercellular digestion
-Can be considered the cells garbage disposal system or recycling centre
-as enzymes, lysosomes break down large complex food into smaller foods so the mitochondria can process them into energy
-Because enzymes are capable of digesting worn out or non-usable cell structures and most foreign substances that enter the cells, lysosomes function as the cells demolition sites.

What is the Golgi apparatus
- Found close to the nucleus and appears as a stack of flattened membrane sacs, associated with swarms of tiny vesicles
- Receives proteins from the Endoplasmic reticulum and send it to the cell membrane for export
- It is generally found close to the nucleus and is the principal “traffic director “for the cellular proteins
- It serves to collect and transfer proteins outside the cell
- gather simple molecules and combines them to make molecules that are more complex – hence your protein
What are centrioles
-Don’t do too much until the cell is ready to divide
- Located close to the nucleus and consists of two tubular structures called centrioles
- Looks like tubes Or rod shaped
- It’s major function is to intervene in the cycle of cell reproduction [mitosis]
- During cell division the centrioles direct the formation of the mitotic spindle
What is the nucleus
- “The leader of our city” contains genetic material and instructions for how the cell is to perform
- protected by a membrane
- Contains all of the cells hereditary genetic material (chroma zones, jeans, DNA)
- Dance active protoplasm found in the centre of the cell
- Controls and regulates the metabolic activities of the cell
- Dictates cell division
-  Important part in reproduction and metabolism
- It also has three distinct regions or structures: the nuclear envelope, nucleoli, and chromatin
- The cell that has lost or rejected its nucleus for whatever reason is programmed only to die
-DNA is also known as deoxyribonucleic acid. Is much like a blueprint that contains all of the instruction needed for building the whole body and instruction for building proteins
What are genes
- A gene is a DNA segment that carries the information for building one protein or polypeptide chain
- Proteins are key substances for all aspects of cell life
- The basic unit of heredity
- Each chromosome has up to 1250 genes which are responsible for physical traits such as body structure, hair and eye colouring etc.
- are the blueprint for protein structure. In addition to replicating itself for cell division DNA serves as the master blueprint for protein synthesis
What were the other parts of the cell mentioned in the lecture which are in the book?
Open the picture below for a very brief description just in case you need to know them
