ultrastructure of eukaryotes Flashcards
What are the organelles that are present in eukaryotic cells? (12)
Nucleus;
Endoplasmic reticulum (Both RER and ER);
Golgi apparatus;
Ribosomes;
Mitochondria;
Lysosomes;
Chloroplasts;
Plasma membrane;
Centrioles;
Cell wall;
Flagella;
Cilia
What organelles are only present in plant cells? (3)
Cellulose cell wall;
Chloroplasts;
Vacuole
Draw and label the structure of a nucleus (4)
Nucleolus;
Nuclear envelope;
Chromatin;
Nuclear pores
What does the nucleus contain within its structure to accommodate for its function? (3)
Histones (protein);
Linear DNA;
One or more RNA nucleoli
What is the function of the nucleus? (2)
Contains and produces genetic material (DNA and RNA);
Controls protein synthesis;
So controls the development and function of the cell
What components make up the structure of ribosomes? (2)
Proteins;
Ribosomal RNA
What is the function of the ribosomes? (2)
Site of translation in protein synthesis;
Translating mRNA sequence into a sequence of amino acids
Draw the structure of the rough endoplasmic reticulum (1)
It looks a lot like a maze with ribosomes on its surface
Describe the function of the rough endoplasmic reticulum (2)
Has ribosomes on its surface that produce secretory proteins (proteins that are released out of the cell);
These secretory proteins are sent to Golgi Apparatus for modification and packaging
What is the difference in structure between the RER & SER? (1)
RER contains ribosomes on its surface, whereas, SER lacks ribosomes
Draw the structure of Golgi apparatus (1)
It looks a lot like a wifi symbol
Describe the several functions of the Golgi apparatus (3)
Adds carbohydrates to proteins received from the RER to form glycoproteins;
Packages proteins/glycoproteins into Golgi vesicles (sacks) for secretion;
Produces lysosomes - a type of Golgi vesicle that releases lysozymes (hydrolytic enzymes)
What is the basic function of the plasma membrane? (1)
Controls the movement of substances into and out of the cell
What are the roles of the organelles that are involved in the production, transport and release of proteins from eukaryotic cells? (5)
- DNA in the nucleus codes for these proteins;
- Ribosomes in the RER produce these proteins via protein synthesis;
- Mitochondria produces the ATP that is required for protein synthesis;
- Golgi apparatus packages and modifies these proteins into vesicles;
- Vesicles fuse with the cell membrane and release proteins outside of cell by exocytosis
Describe the functions of lysosomes (3)
Digests material that is taken in by phagocytosis;
Non-functioning organelles within the cell are engulfed and digested by lysosomes;
Releases enzymes outside of the cell
Draw and label the structure of the mitochondria (8)
Matrix;
Enzymes;
Inner membrane;
Cristae;
(Circular) DNA;
Inter-membrane space; Ribosomes (70S);
Outer membrane
What is the basic function of the mitochondria? (2)
Involved in aerobic respiration;
Which produces ATP
Why may some cells have lots of mitochondria and could you give an example of a cell? (2)
To provide energy to cells that require a large amount of ATP;
E.g. muscle cells
What is the basic function of the cell wall? (1)
Provides support, strength and shape to the cell
What is the basic function of the chloroplasts? (2)
Contains chlorophyll;
Which absorbs light energy for photosynthesis (important for the light dependent stage of photosynthesis)
Draw and label the structure of chloroplasts (8)
Lipid droplets;
Stroma;
Thylakoids;
Free ribosomes (70S);
Circular DNA;
Starch grains;
Membrane bound chromosomes;
Granum
What is the granum that is found in chloroplasts? (1)
Stacked thylakoids
How do granum join together to form grana (plural for granum)? (1)
Link together by thin pieces of membrane - lamellae
What is the basic function of the large vacuole? (1)
Contains soluble sugars, salts and pigments
What features of both chloroplasts and mitochondria demonstrate that they are formerly free-living bacteria that were absorbed into a larger cell? (2)
They both contain circular DNA;
They both contain 70S ribosomes
What are centrioles? (2)
Cylindrical structures found in animal cells;
Component of cytoskeleton
Draw the structure of centrioles (2)
Composed of microtubules;
9 microtubules organised into triplets
What is the function of the centrioles? (2)
Two centrioles at right angles to each other form a centrosome;
This organises the spindle fibers during cell division
Draw the structure of cilia (2)
Hair-like projections;
Made of microtubules
What is the function of cilia? (2)
Allow the movement of substances over the cell surface
Draw the structure of flagella (2)
Similar structure to cilia;
Made of longer microtubules
What is the cytoskeleton? (1)
Network of protein filaments and tubules in the cytoplasm of many living cells
What is features form the importance of the cytoskeleton? (4)
Provides mechanical strength to cells;
Aids in the movement of molecules within the cell;
Maintains the shape of cells;
Forms both cilia and flagella
What structures of the cytoskeleton allow it to carry out its function? (1)
Microtubules
