Chapter 3: Cell structure Flashcards
LEarn about how cells are studied, microscopes, the structure of prokaryotic and eukaryotic cells, cell specialisation, mitosis and the cell cycle
cell surface membrane
- regulates the movement of substances in and out of the cell
- mainly made of lipids and proteins
- fluid-mosaic model
- has receptor molecules which are needed for cell recognition and responding to chemicals such as hormones
nucleus
- controls the cell’s activity by controlling the transcription of certain genes
- nuclear envelope
- nuclear pores
- contains chromosomes/DNA
- nucleolus
Mitochondria
- site of aerobic respiration
- site of ATP production
- double membrane
- cristae: folds of inner membrane
- matrix: enzymes involved in respiration
Golgi apparatus
- processes and packages proteins and lipids
- makes lysosomes
- fluid filled sacs
- vesicles
Lysosomes
- fluid filled sacs
- digestive enzymes called lysozymes
- break down worn out parts of cell and digest invading cells
Golgi vesicles
- stores lipids and proteins
- transports out of cell
- fluid filled sacs
- produced by Golgi
Ribosome
- site of protein synthesis
- floats free or attached to RER
- made up of proteins and RNA
Rough endoplasmic reticulum
- folds and processes proteins
- ribosomes
Smooth endoplasmic reticulum
- no ribosomes
- synthesises and processes lipids
Cell wall
- plant, algae** and **fungi
- structural support
- rigidity
- cellulose
- chitin
Chloroplast
- site of photosynthesis
- plants and algae
- thylakoids: fluid filled scas
- grana: stacks of thylakoids
- stroma: gel-like; enzymes sugars organic acids
- double membrane
Cell vacuole
- helps maintain pressure inside cell
- filled with cell sap: solution of salts and sugar
- turgidity - prevents wilting
- membrane called tonoplast
What is a plant cell wall made of?
cellulose
What is a fungal cell wall made of?
chitin
What is a tissue?
a group of cells that work together do a similar job
What is the function of ribosomes?
Ribosomes are a cell structure that makes protein. Protein is needed for many cell functions such as repairing damage or directing chemical processes. Ribosomes can be found floating within the cytoplasm or attached to the endoplasmic reticulum.
What is the function of mitochondria?
The main job of mitochondria is to perform cellular respiration. This means it takes in nutrients from the cell, breaks it down, and turns it into energy. This energy is then in turn used by the cell to carry out various functions. The mitochondria are in charge of producing the energy currency of the cell, ATP during respiration.
What is the function of chloroplasts?
Chloroplasts job is to convert light energy from the sun into sugars that can be used by cells. The entire process is called photosynthesis and it all depends on the little green chlorophyll molecules in each chloroplast.
What is the function of the SER and the RER?
The rough endoplasmic reticulum is an organelle that produces proteins and helps them fold properly. The smooth endoplasmic reticulum is another organelle that synthesizes lipids. It produces phospholipids and cholesterol that help stabilize the membranes of the entire cell.
Viruses are acellular. What does this mean?
It means that they are not really cells so they aren’t alive. They are actually nucelic acids surounded by protein
What is the structure of a virus?
- no plasma membrane - no ctypolasm - no ribosomes - protein coat called capsid - genetic material - attachment proteins
What is the structure of a virus?
- no plasma membrane, ctypolasm, ribosomes or nucleus - protein coat called capsid - genetic material - DNA or RNA - attachment proteins
How do viruses replicate?
They use host cells to replicate themselves - attachment proteins bind to complimentary receptor proteins on surface of host cell - different viruses have different attachment proteins - viruses can be specific to one type of cell and some viruses can infect lots of cells - viral genetic material injected into host cell - host cell uses its own machinery (enzymes and ribosomes) to manufacture the components to make new viruses
How do viruses replicate?
They use host cells to replicate themselves - attachment proteins bind to complimentary receptor proteins on surface of host cell - different viruses have different attachment proteins - viruses can be specific to one type of cell and some viruses can infect lots of cells - viral genetic material injected into host cell - host cell uses its own machinery (enzymes and ribosomes) to manufacture the components to make new viruses
What are microtubules?
Microtubules are long, hollow, cylindrical structures made of a protein called tubulin. They run in all directions through the cytoplasm making up the cytoskeleton.
