Topic One - Organelles and stuff Flashcards
cell theory
all organisms are composed of cells
cells are the smallest unit of structure for all living things
cells arise only from pre-existing cells, all cells today come from the start.
What do all cells have in common
DNA, Cytoplasm, Plasma membrane
Functions
- Metabolism
Chemical reactions inside the cell
Functions
- Response
perceiving and responding to changes in the environment
Functions
Homeostasis
keeping the conditions inside the organisms within tolerable limits (balanced)
Cell Membrane
The outer membrane of the cell that controls movement in and out of the cell
It has a double layer
- a physical barrier for the cell
separated internal and external environments
semi-permeable
- outer surface surrounding the cell
Cell wall
ound in plant cells & bacteria, not found in animal cells
Supports & protects cells
Nucleus
Directs cell activities – “control center”
Separated from cytoplasm by nuclear membrane
Contains genetic material - DNA
Chromosomes
Inside nucleus
Made of tightly coiled DNA
Contain instructions for traits & characteristics
Cytoplasm
Gel-like mixture
Surrounded by cell membrane
All organelles are surrounded by cytoplasm
Endoplasmic Reticulum
Moves materials around & makes proteins
Smooth type: lacks ribosomes
Rough type (pictured): ribosomes embedded in surface
Ribosomes
Each cell contains thousands
Make proteins
Found on ER & floating throughout the cell
Mitochondria
Produces energy through chemical reactions – breaking down fats & carbohydrates
Powerhouse of the cell, creating energy for the cell to use
Golgi Bodies
Protein ‘packaging plant’
Move materials within the cell and out of the cell
Sorting, tagging, packaging, and distributing proteins
Lysosome
Digestive ‘unit’ that breaks down material in cell that is not needed and remove it from the cell
Cell breaks down if lysosome explodes
Vacuoles
Membrane-bound sacs for storage, digestion, and waste removal
Contains water solution
Help plants maintain shape
Large in plants, small in animals
Chloroplast
Usually found in plant cells
Contains green pigment chlorophyll
Where photosynthesis takes places
has grana
centrioles
exist in pairs
Fluid Mosaic model
- the components are free to move freely from each other.
- the ‘heads’ face the exterior and interior
- the tails are in the middle
The phospholipid Bi-Layer - Heads
Hydrophilic - Water-loving, polar
The phospholipid Bi-Layer - Tails
Hydrophobic - Water-hating, non-polar
microscopes
magnification = size of image / actual size of the object
DNA structure
Deoxyribo Nucleic Acid
One molecule of DNA consists of
- 2 strands of repeating units called nucleotides
The 2 strands are twisted in a double helix
DNA - Circle, pentagon, rectangle
Phosphate, Deoxyribos sugar, nitrogenous base
RNA - Circle, pentagon, rectangle
Phosphate, Ribose sugar, nitrogenous base
the genetic code
gene - a sequence of bases in DNA that codes for an amino acid in a protein.
What are the nucleotides - DNA
A-T, C-G = Bases in DNA
mRNA
A-U, C-G = Bases in RNA
what are the two types of proteins
1 - Structural
2 - Functional
What are proteins made of
Proteins are long molecules made from chemical units called amino acids.
A gene codes for a particular amino acid
Amino acids join together to make a specific protein.
Different combinations of amino acids make different proteins.
2 steps of protein synthesis are …
transcription and translation
Transcription
Takes place inside the nucleus
DNA unzips (one gene) and a complimentary copy of this gene called
mRNA (messenger RNA) is formed from RNA nucleotides
The newly formed mRNA leaves the nucleus through the nuclear pore
Translation
takes place in the cytoplasm
the mRNA is run through the ribosome, where the triplet is read. each triplet is called a codon.
tRNA has the anti-codon which brings specific amino acids to the triplet
a specific sequence of amino acids folds to become a protein
the synthesis of ATP occurs in
The mitochondria
prokaryotes
simple cell, no nucleus, free-floating DNA
10 times smaller than plant and animal cells
- archaea
- bacteria
flagellum
protein secretory pathway
synthesised in the ribrosomes on the rough ER, golgi body, vesicles out of the cell,
Eukaryotes
- has embrace-bound organelles
- has a nucleus
- classifications groups fit into plants, animals, fungi and protists. (they all have membrane-bound organelles)
plant cells exclusively have
Chloroplast, cell wall, vacuole
what is the difference between plant, animal and bacteria cells
plant and animal are eukaryotes
bacteria is prokaryotic
difference between DNA and RNA
- the sugars, deoxyribose and ribose
- t becomes u
- DNA is double-stranded
- RNA is single-stranded
