Pack 2 - Cells Flashcards
What is cell theory?
- The cell is the most basic unit of life
- All living organisms are composed of one or more cells
3, All cells arise from pre-existing, living cells
Define Eukaryote
An organism whose: -cells contain a true nucleus (surrounded by the nuclear membrane)
- cells contain other membrane-bound organelles
- genetic material (DNA) is contained within the nucleus and is organised in chromosomes
List 13 Parts of a Eukaryotic animal cell
Mitochondrion Ribosome RER SER Plasma membrane Cytoplasm Lysosome Golgi apparatus Nucleus: -Nucleolus -Chromatin -Nuclear pore -Nuclear envelope
Define intrinsic
Running through the membrane
Extrinsic
Outside the membrane
List 7 parts of a Eukaryotic plant cell that aren’t in an animal cell
Filamentous cytoskeleton Cell wall Chloroplast -Thylakoid membrane -Starch grain Vacuole - Tonoplast
How would you describe the RER to the nuclear envelope?
Contiguous
Define cisternae
Hole inside a cavity
List 6 parts of a nucleus
Nuclear envelope -RER -Cisternae Nuclear pores Chromatin Nucleolus
What are the functions of a nuclear envelope?
Control entry and exit of substances
Contain reactions inside the nucleus
What is the function of nuclear pores?
Allow passage of large molecules out of the nucleus (eg. mRNA)
What is the function of the nucleolus?
Manufactures rRNA
Assembles Ribosomes
Define protein bound
DNA wound around proteins called histones
What are ribosomes made of?
Large subunit
Small subunit
How are proteins synthesised in the ribosomes?
tRNA carrying amino acids - depends on which the mRNA calls for
mRNA carries the genetic information - each of which codes for a particular amino acid
rRNA associates with a set of proteins to form ribosomes
Multiple amino acids are strung together, creating proteins
Describe a prokaryotic ribosome
70S - around 20nm in diameter
Describe a eukaryotic ribosome
80s - around 25nm in diameter
What is the function of ribosomes?
Site of protein synthesis
What is the function of RER?
Pathway for transport of materials, especially proteins through the cell
What is the function of SER
Synthesises, stores and transports lipids
Synthesises, stores and stransports carbohydrates
How is the RER adapted to be particularly effective at protein synthesis
Large surfave area to volue ratio
Name 2 parts to the Golgi apparatus
Vesicles
Cisternae
Give 5 functions of the Golgi apparatus
Adds carbohydrates to proteins to form glycoproteins
Produces secretory enzymes (eg in the pancreas)
Secretes carbohydrates (eg those used in plant cell walls)
Modifies/processes triglycerides
Combines triglycerides with proteins
Forms lysosomes
What is a Golgi vesicle?
A small, rounded, hollow structure
That transports substances to and from the Golgi apparatus.
Some of these are lysosomes.
What is the difference between a Golgi vesicle and a lysosome?
A lysosome is a vesicle that stays inside the cell.
How to vesicles leave and join organelles?
Pinch off
Fuse
Give 4 functions of lysosomes
Hydrolyse material engulfed by phagocytic cells
Release enzymes to the outside of the cell to destroy material around the cell (exocytosis)
Digest worn out organelles so that chemicals may be re-used
Completely break down cells after they have died (autolysis)
Give the approximate size of a lysosome
Up to 1μm in diameter
Define exocytosis
The release of enzymes to the outside of the cell to destroy material around the cell
Define autolysis
Completely breaking down cells after they have died
List 4 parts of a mitochondrion
Outer membrane
Inner membrane
Intermembrane space
Cristae
State 3 things about mitochondria
Rod shaped, 1-10μm in length
Site of aerobic respiration
Produce ATP
Why do mitochondria sometimes appear to be round in microscope images?
They look round when cut transversely
How is energy released from glucose?
Mitochondria are the site of aerobic respiration
Mitochondria require glucose in the manufacture of metabolic energy (or ATP)
What type of cell would have many mitochondria?
A metabolically active cell eg muscle (Contraction) or epithelial (Active Transport)
Why do tissues that perform active transport require a lot of mitochondria?
Mitochondria are the site of aerobic respiration
Respiration produces ATP
ATP is needed for active transport
Why might someone with mitochondrial disease find exercise difficult?
Mitochondria are the site of aerobic respiration
Respiration produces ATP/releases energy
Energy/ATP is needed for muscle contraction
What does the energy do from respiration that results in ATP
ADP + P -> ATP
Name 12 parts of a chloroplast
Ribosome Plastoglobule Internal membrane Intermembrane space External membrane Granum Chloroplast DNA Stroma Lamella Lumen Thylakoid membrane Thylakoid
How long is a chloroplast?
2-10μm in length
What is the function of a chloroplast?
Site of photosynthesis
How is a chloroplast adapted to its function?
Grana - large surface area to volume ratio for attachment of: - chlorophyll - electron carriers - enzymes (for 1st stage of photosynthesis).
Stroma - contains enzymes
(for 2nd stage of photosynthesis).
DNA and ribosomes - for quick protein synthesis for photosynthesis
Where are chloroplasts found?
Plants and algae
Name 2 parts of a vacuole
Vacuole
Tonoplast