The Cell Flashcards
Define a cell
The smallest unit of matter that can live independently and reproduce itself.
What is the study of cells called?
Histology
List all structures that could be found within a cell.
Cell membrane
Cytoplasm
Mitochondria
Ribosomes
Endoplasmic reticulum
Smooth endoplasm reticulum
Golgi apparatus
Lysosomes
Centrosomes
Centrioles
Nucleus
Nucleolus
Nucleoplasm
Chromatin
Chromosomes
What is cytoplasm and what is its function?
Protoplasm inside the cell but outside of the nucleus
Made from water, inorganic and organic salts, lipids, carbohydrates, nitrogenous substances (amino acids).
Suspends all organelles in cell
What is the mitochondria and what is its function?
Power house of cell. Has chemical reactions which produce energy and release ATP for cell to use
What are the ribosomes of a cell and what are their function?
Protein factories. Create proteins and enzymes for growth and repair
What is rough endoplasmic reticulum and what is its function?
Circulatory system of a cell. Has ribosomes on its surface and processes the proteins made by the ribosomes.
What is smooth endoplasmic reticulum and what is its function?
Smooth endoplasmic reticulum is also the cells circulatory system but produces lipids and steroids
What is the Golgi apparatus and what is its function?
Main function is to produce lysosomes. GA also transports the proteins from the endoplasmic reticulum into the rest of the cell.
What is a lysosome in the cell and what is its function?
Lysosomes are organelles with digestive enzymes in them that destroy old cells as well as break down food to produce and release ATP into the greater cell.
What is a centrosome and what is its function?
Centrosomes are dense areas of cytoplasm that hold the centrioles and where spindle fibres form during cell division
What is a centriole and what is its function?
Two organelles lying at right angles to one another that are pulled apart and aid cell division in mitosis
What is a nucleus and its function?
Largest organelle within the cell. Is the centre that controls growth, repair and reproduction. Has its own set of structures within it.
What is the nucleolus and its function?
Small bodies/ organelles. Usually 1-2 within each nucleus and its function is to control ribosome production, sending them out into the greater cell once made.
What is chromatin and its function?
Loosely coiled DNA strands which during cell division become tightly coiled and form chromosomes
What is nucleoplasm and its function?
Type of protoplasm found only in the nucleus. Suspends the nucleus structures within the nucleus and provides nutrients and chemicals required by these structures.
What is a chromosome and its function?
Two chromatids of DNA held together by a centromere. DNA is organised into genes that control activity and inheritance
What is the cell membrane and its function?
Semi permeable membrane made of lipids and proteins. 2 functions; to keep organelles in and let fats/proteins etc out
What are the 5 ways substances can enter or leave a cell?
Diffusion
Osmosis
Dissolution
Active transport
Filtration
What is diffusion?
When a substance moves from high/strong concentration/pressure solution to a low/weak concentration/ pressure solution until both solutions equal/balanced
What is osmosis?
When water molecules move from a high concentration solution to a low concentration solution due to osmotic pressure. When balance occurs, isotonic pressure is achieved.
What is dissolution?
Substance dissolves through the phospholipid membrane into the cell where it then dissolves further in the cytoplasm.
What is active transport?
When a substance is too big or doesn’t dissolve in fat, it is carried by a carrier substance across the cell membrane. Energy is required for this form of movement.
What is filtration?
When water and substances push on the cell membrane changing the pressure and forcing movement across the membrane.
What is the function of a cell and how can it be remembered?
Function changes depending on type of cell. Way to remember all functions is MRS GREM
Explain the acronym MRS GREM to remember the functions of a cell.
M - movement
R - respiration
S - sensitivity
G - growth
R - reproduction
E - excretion
M - metabolism
Define anabolism.
Chemical reaction within a cell to create new products for growth and repair ie proteins
Define catabolism.
Chemical reaction which breaks a substance down into its simplest form eg CO2 or ATP.
How does a cell turn into a functioning human body?
Cells of the same function make tissue
Tissue of the same function make organs
Organs of a similar function make systems
Systems working cohesively in one body creates an organism
What are the two types of reproduction certain cells can undergo?
Mitosis - genetically identical
Meiosis - genetically variable
What are the 4 (or 5) stages of mitosis?
Prophase, metaphase, anaphase and telophase (interphase if counted).
What occurs in the prophase stage of mitosis?
Centrosome splits in half, also splitting the centrioles apart. Now held together by spindle fibres
Chromatids condense to form chromosomes
Nucleolus disappears
What occurs in the metaphase stage of mitosis?
Centrioles move to opposite poles of cell
Chromosomes are attached to centrioles by spindle fibres, arrange themselves in centre of the cell and start being pulled apart into separate chromatids by centrioles
Nuclear membrane disappears
What occurs in the anaphase stage of mitosis?
Cell membrane dimples starting to create two separate cells
Chromatids pulled further apart creating identical halves of pairs pulled to opposite side of cell
Spindle fibres start to make new centromeres
What occurs in the telophase stage of mitosis?
Spindle fibres disintegrate and centrioles replicate
Nuclear membrane forms around chromatids
Cell membrane continues to constrict until two daughter cells are created, identical to parent cell
What occurs in the interphase stage of mitosis?
First stage before prophase. Where the cell begins to prepare for cell division. The cell grows bigger and DNA chromatin is doubled.
What happens in meiosis?
Reproduction of sex cells resulting in a gamete
Chromosomes are not pulled apart at the centromere, meaning full chromosomes move to pole ends of the dividing cell
This means half the number of chromosomes enter into each new cell
A zygote is created when a sperm fuses with an ovum to recreate the full 46 chromosomes a cell should have
The zygote then divides by mitosis to form an embryo
