How do Cells do What They do? Flashcards
What is a cell
the fundamental structural and functional unit of all living things
What are the functional characteristics of cells?
cell metabolism (chemical reactions): production of energy. oxygen and glucose are used to create proteins and hormones
synthesis of molecules: cells ability to create RNA and proteins
Communication: cell communication with surroundings and each other by sending and receiving electrical signals
Reproduction / inheritance: the ability to divide and reproduce, passing genetic material to daughter cells
What are the key components of the cell?
plasma membrane
cytoplasm
nucleus
Cytoplasm
FUNCTION: Fluid material outside the nucleus but within plasma membrane
STRUCTURE:
cytosol: fluid portion with ions and proteins
cytoplasmic inclusions: aggregates of chemicals
cytoskeleton: supports the cell and its organelles and aids in cell shape. contains microtubules, microfilaments and intermediate filaments
Nucleus
FUNCTION: Control centre of the cell that houses DNA (carries code for structural and functional traits)
STRUCTURE:
Nuclear envelope: bilayer surrounding nucleus
Nucleolus: produces ribosomes
Chromatic: long strand of DNA and proteins that condense into chromosomes during cell division
Ribosomes
FUNCTION: The site of protein synthesis where amino acids are assembled into proteins
STRUCTURE:
2 sub units (large and small)
can be free floating in cytoplasm or attached to endoplasmic reticulum
plasma membrane (cell membrane)
FUNCTION: security gate/ perimeter around the cell and supports the content of the cell. regulates what enters and exits and has receptors for cell communication.
STRUCTURE: phospholipid bilayer for flexibility.
Lipid bilayer: polar heads (hydrophilic) and non-polar tails (hydrophobic)
contains proteins (45-50%), carbohydrates (4-8%), and a fluid mosaic model structure.
Glycocalyx is the outer surface of the cell membrane
endoplasmic reticulum (ER)
FUNCTION: A network of interconnected sacs and tubules.
- rough ER: synthesises and modifies proteins
- smooth ER synthesises lipids, steroids and carbohydrates, breaks down harmful chemicals and glycogen
STRUCTURE: rough ER is studded with ribosomes while smooth ER has no ribosomes
golgi apparatus
FUNCTION: modifies, packages and prepares proteins and lipids made by ER for distribution
STRUCTURE: stacks of flattened membranes
lysosomes
FUNCTION: contains enzymes that digest waste products (molecules) not needed anymore by the cell.
including nucleic acids, proteins and lipids
STRUCTURE: membrane bound vesicles formed by golgi apparatus
mitochondria
FUNCTION: ‘power house of the cell’, breaks down food molecules into ATP
STRUCTURE: Outer membrane, Inter-membrane, inner membrane and matrix.
Contains genetic material and can reproduce on its own
centrioles
FUNCTION: cell division
STRUCTURE: barrel shaped organelles arranged at right angles, made of microtubules. 2 centrioles are found in the centrosome
cilia
FUNCTION: movement of substances across the surface of cells
STRUCTURE: whip like, motile cellular extensions which project from outer surfaces of certain cells
flagella
FUNCTION: motility of the entire cell
STRUCTURE: longer than cilia, only found on sperm cells
microvilli
FUNCTION: increase surface area of cell, enhancing ability to absorb materials
STRUCTURE: extensions of plasma membrane that do not move
What is histology?
The study of tissues. aims to understand micro anatomy of cells, tissues and organs
What is haematoxilyn and eosin? (H&E)
Most common type of stain. stains nuclei and cytoplasm.
Haematoxilyn stains nuclei purple
Eosin stains cytoplasm pink
What is the order of preparation of tissue?
- remove tissue from the body through a biopsy or autopsy
- fixation of tissue (para-formaldehyde)
- embed tissue (wax)
- slice the tissue and put onto glass slide
- staining and viewing the tissue with microscope
What are the primary tissues? what do they do?
Epithelial - covers
connective - supports
muscle - movement
nervous - control
