Cells Flashcards
What organelles have internal cell plasma membranes ? (7 answers)
Endoplasmic Reticulum, Golgi Apparatus, Nucleus, Mitochondria, Lyosomes, Endosomes, Chloroplast
What are the 4 main functions of the internal cell membranes around the organelles ?
- Provides a transport system
- Separates different regions in the cell
- Allows specialisation in the different regions
- Creates a large surface area for enzymes to attach.
What are the two types of endoplasmic reticulum?
Smooth and Rough Endoplasmic Reticulum.
What is the structure of endoplasmic reticulum?
It forms a system of flattened, membrane enclosed sacs (cristernae) which are continuous with the outer nuclear membrane.
What is the function of Smooth ER?
Smooth ER provides synthesis and transport of lipids.
What is the function of Rough ER?
Rough ER transports synthesised proteins (synthesised by attached ribosomes)
What is the structure of a Centriole?
Two hollow cylinders positioned perpendicular to one another.
What is the function of a Centriole?
It is used in a spindle formation (microtubes) in cell division.
What is the structure of a ribosome?
Its made from two subunits (ribosomal RNA and protein)
What is the function of ribosomes?
Protein Synthesis
Where are ribosomes found within the cell? (3 Answers)
- Attached to ER
- ‘Free’ in Cytoplasm
- Attached to mRNA strands to create a polysome structure.
What is the basic structure of a virus?
It contains two basic components, nucleic acid (single or double-stranded RNA or DNA) and a protein coat - the capsid.
What is the function of a chloroplast?
Photosynthesis
What is the structure of the Golgi Body/ Apparatus?
Similar to Endoplasmic Reticulum but more compact. It is surrounded by vesicles.
What is the function of the Golgi Body/ Apparatus?
A major function is the modifying, sorting and packaging of proteins for secretion. It is also involved in the transport of lipids around the cell and the creation of lysosomes.
What is the structure of a lysosome?
Small vacuoles are formed when parts of the Golgi body are pinched off.
What is the function of a lysosome?
Contain and isolate digestive enzymes, release enzymes to destroy organelles, digestion of material taken into the cell .e.g. Bacteria.
What are the organelles found only in plant cells?
A Cell Wall, a large central vacuole, plastids such as chloroplast.
What are the organelles found in both plant and animal cells?
Mitochondria, ER, Cell membrane, Golgi Apparatus, Nucleus, Cytosol, Peroxisomes, Cytoskeleton.
What are the organelles found only in animal cells?
Lysosomes and Centrosomes.
What is the definition for a specialised cell?
Modified cells to carry out a particular function.
What is the definition for a tissue?
A tissue is an ensemble of similar cells that carry out a specific function.
What is the definition of an organ?
Organs are formed by the functional grouping together of multiple tissues.
Give an example of a specialised cell, one tissue and an organ.
Cardiac muscle cell, muscular tissue, the heart.
What is the structure of a vacuole?
Vacuoles are membrane-bound sacs within the cytoplasm.
What are vacuoles also called in animal cells?
Lysosomes
What is the function of a plant cell vacuole?
to hold material and wastes, and maintain the proper pressure within the plant cell to provide structure and support.
What is the function of a animal cell vacuole?
Store a variety of nutrients and waste products to prevent contamination.
What is the structure and function of the nucleus?
Structure - contains a nuclear membrane, chromosomes, nucleolus and cytoplasm.
Function- to store the genetic information.
What is chromatin?
The material of which the chromosomes of organisms, other than bacteria, are composed. (Consisting of protein, RNA and DNA)
What is the function of the nucleolus?
Combine ribonucleic acids (RNA) with proteins to make rRNA.
What are the similarities of Prokaryotes and Eukaryotes cells?
.They are both cells
.They both have cell membranes
.They both have ribosomes
What organelles do only Prokaryotic Cells have?
.Nucleoid
.Circular DNA
What organelles do only Eukaryotic Cells have?
.Nucleus
.Organelles
.Linear DNA
Finish the equation CO2 + H20 =
02 + C6H2O6
What is the function of Mitochondria?
Aerobic Respiration
What is the function of Ribosomes?
Protein Synthesis
What is the function of Nuclear Envelope?
Contains the nucleoid
What is the function of Nucleolus?
Makes rRNA
What is the function of Smooth Endoplasmic Reticulum?
The synthesis and transport of lipids
What is the function of Rough Endoplasmic Reticulum?
To transport synthesised proteins
What is the function of the nuclear pore?
Allows movement of substances into and out of the nucleus
What is the function of a Vesicle?
Assists with the exocytosis process
What is the function of the Golgi Body?
The modifying, sorting and packaging of proteins in addition to the transport of lipids and creation of lysosomes.
What is the function of Plasmodesmata?
Allows communication between cells
What is the equation for calculating magnification?
Size of Image/ (Actual size of specimen X Magnification)
What is the definition of a Eukaryotic Cell?
Eukaryotic cells include plant and animal cells. They have a “true nucleus” meaning the nucleus is membrane bound. The nucleus contains chromatin which is the DNA tightly wrapped around histone proteins.
What is the definition of a Prokaryotic cell?
Prokaryote cells include bacterial cells. They have no “true nucleus” meaning the genetic material (DNA) is free in the cytoplasm in an area called the nucleoid.
What type of ribosomes are found in Eukaryotic cells?
80’s ribosomes
What type of ribosomes are found in Prokaryotic cells?
70’s ribosomes
What type of DNA is found in Eukaryotic cells?
Linear
What type of DNA is found in Eukaryotic cells?
Circular
What is the function of Flagellum?
Makes the bacterium motile
What is the function of Capsule?
A layer of slime for mobility
What is the cell wall made up of in Bacterium?
Amino Acids and polysaccharides (made of peptidoglycan)
What is the function of Reverse transcriptase enzymes ?
Changes RNA into DNA to integrate into cells
What is the capsid?
A protein coat which surrounds the RNA/ DNA
What is the function of a chromatophore in bacterium?
Contains chlorophyll for photosynthesis
What is the function of a mesosome in a bacterium?
Respiration in bacteria
What is a plasmid ?
A small circular piece of DNA in bacterium
What are the four main types of tissue?
- Epithelial
- Connective
- Muscular
- Nervous
What is epithelial tissue?
Living tissue, where cells are packed closely together
Where is epithelial tissue found?
On the surface of organs, cavities and tubes.
Do epithelial cells divide quickly or slowly?
Quickly
What is the structure of squamous cells?
Thin and smooth
What is the function of squamous cells?
Create a short diffusion distance
Where are squamous cells found?
Alveoli, capillaries etc.
What is the structure of cuboidal cells?
Boxed shape
What is the function of cuboidal cells?
Used for secretion and absorbtion
Where are cuboidal cells found?
Glands and kidney tubules
What is the structure of columnar epithelial cells?
Column shaped, some have cilia and some have microvilli.
What is the function of columnar epithelial cells?
Making and secreting mucus
Where are columnar epithelial cells found?
Lungs, Bronchi and oviducts
What does connective tissue contain?
The protein collagen in the extracellular material
What is the function of connective tissue?
To connect other tissues
What are the three types of Muscular tissue?
- Smooth
- Cardiac
- Skeletal
What are the protein fibres that shorten the muscular tissues?
Actin and Myosin
What is the function of muscular tissue?
Contract and relax
What is the function of skeletal tissue?
Moves whole parts of the organism
What is the structure of skeletal tissue?
Muscle cells are joined together to form fibres. The striations are cause by overlapping protein molecules.
Where is skeletal tissue located?
All over the body
What is the structure of smooth muscle?
Unstriated, individual cells which can shorten in length
What is the function of smooth muscle?
They move the body without conscience thought
Where is smooth muscle located?
Found in the blood vessels and gut.
What is the structure of cardiac muscle?
Striated and branched fibres which are joined by thick membranes called intercalated discs.
What is the function of the cardiac muscle?
They carry out the involuntary contractions of the heart.
What are the 7 steps of the cell, tissues and organs cycle?
- Simple molecules
- Complex molecules
- Cell
- Tissue
- Organ
- Organ systems
- Organism
What is the first step of protein synthesis?
The nucleus contains DNA which codes for amino acids sequences in a protein
How is the mRNA copy of the DNA made in protein synthesis?
Transcription
How does the mRNA copy of the DNA leave the nucleus in protein synthesis?
Through a nuclear pore
What happens in protein synthesis after the mRNA is made?
The nucleolus makes ribosomes
What synthesises the proteins using mRNA in protein synthesis?
Ribosomes
What transports the proteins during protein synthesis?
Rough endoplasmic reticulum
What does the Golgi Body do in protein synthesis?
Modifies proteins which are then packaged into an excretory vesicle.
What does the vesicle migrate towards in protein synthesis?
The plasma membrane
What is exocytosis?
The process of a vesicle fusing with the plasma membrane and its contents being emptied.