Cells
building blocks of life
Differentiation
process in which cells become specialized in structure and function
expressed gene in differentiation
switched on
unexpressed gene in differentiation
switched off
organelles
structures found inside cells that perform a specific function
prokaryotic cells
simple cells that lack a cell nucleus and membrane-bound organelles
Prokaryotes
single-celled organisms that don't contain a nucleus or any membrane-bound cell organelles
prokaryote example
Bacteria and Archaea
cytoplasm
gel-like substance enclosed within the cell found where cellular chemical reaction take place
Nucleoid
A dense region of DNA in a prokaryotic cell
Ribosmes
plasma membrane
surrounds the cell and separates the contents of the cell from its surroundings
unicellular organism
An organism made up of one cel in which the single cell is responsible for carrying out all functions of life that are nesscary for its survival
Unicellular example
bacteria, amoeba, chlorella, paramecium, euglena
Metabolism
All of the chemical reactions that occur within the cell
Multicellular
Made up of more than one cell, differentiate to make differentiate to make different tissues that pefrom specialised functions
multicellular example
plants and animals
plasmid
A small ring of DNA that helps bacteria to adapt to unusual situations such as antibiotic resistance
Pili
hair-like structures found on surface which helps bacteria adhere to each other for the transfer of DNA from one cell to another by process called conjugation
Flagella
whip-like structure that helps bacteria move around
cell wall
A rigid layer of nonliving material that maintains cell shape + prevents it from bursting, made of peptidoglycan
Ribosomes
protein synthesis
prokaryotic ribosomes
70s
S (Ribosome units)
how fast molecule will sediment centrifuged
ATP (adenosine triphosphate)
high energy molecule which is composed of adenosine and three phosphate groups
ATP function
transfer and storage of energy for chemical reactions that take place in the cell
Nucleolus
ribosome synthesis
Synthesis
combining parts into a whole
Nucleus
surrounded by a phosphorus double membrane
Nucleus function
Contains DNA (genetic information that controls the cell)
mitochondrion
contains own ribosomes + DNA, made of two membranes (outer and inner which is folded inwards to increase surface area)
Mitochondrion function
is cellular respiration, facilitating the production of ATP
aerobic respiration
requires oxygen
Lysosomes
contains many enzymes
Lysosomes function
Digestion and recycling dead organelles + foreign particales
Rough Endoplasmic Reticulum
network of tables that extend from the nucleus to the rest of the cell
Rough Endoplasmic Reticulum function
protein synthesis and transport
Smooth Endoplasmic Reticulum
no ribosomes of the surface
Smooth Endoplasmic Reticulum function
Synthesises and processes lipids
Golgi apparatus (eukaryotic animal cell)
many flattened sacs stacked one top of each other, has two sides (cis (receives products from endoplasmic reticulum), trans side (vesicles are released))
Golgi apparatus function (eukaryotic animal cell)
processes proteins received through RER (packaging + modifying proteins to be used either inside the cell or excreted outside the cell)
Magnification
the ratio of an object's image size to its real size
Resolution
clarity of the view or image
Vacuoles
Cell organelle that stores materials such as water, salts, proteins, and carbohydrates
chloroplasts
surrounded by two membranes; contains own ribosomes + DNA+ captures energy from sunlight and use it to produce food for the cell
Hydrophobic
repelled by water (non-polar)
Hydrophilic
attracted to water (polar)
phospholipid bilayer
a two-layered arrangement of phosphate and lipid molecules that form a cell membrane, the hydrophobic lipid ends facing inward and the hydrophilic phosphate ends facing outward
intergral proteins
membrane proteins that penetrate the phospholipid bilayer
peripheral proteins
membrane proteins that remain on surface
stem cells
undifferentiated cells that can divide and differentiate into different types of cells
hematopoietic stem cells
produce blood cells in bone marrow
embryonic stem cells (for)
easy to obtain
pluripotent
unlimited growth potential
less chance of malignant tumours developing
less chance of genetic damage due to mutations with adult stem cells
embryonic stem cells (against)
destruction of embryo
possible tumor development
likely to be genetically different
adult stem cells (for)
no destruction of embryo
low tumour development chance
no chance of rejection (compatible with adult tissues)
no kill
adult stem cells (against)
limited differentation
not obtained easily sometimes
less growth potential
cord blood stem cells (for)
easily obtained
pluripotent
no embryo destruction
tumor development chances are low
no rejection
differentiation able
cord blood stem cells (against)
has to be obtained immediately after birth
limited quantities where
dilute solution
a solution that contains a small amount of solute dissolved in solvent
concentrated solution
a solution containing a large amount of solute dissolved in solvent
aqueous solution
a solution in which water is the solvent
soloution
a homogeneous mixture of two or more substances (the solutes) dissolved in another substance (the solvent)
simple diffusion
movement of a solute from an area of high concentration to an area of low concentration
Osmosis
Diffusion of water through a selectively permeable membrane, from hypotonic to hypertonic
hypotonic
Having a lower concentration of solute
hypertonic
Having a higher concentration of solute
isotonic solution
A solution in which the concentration of solutes is essentially equal to that of the cell which resides in the solution
turgid
swollen as from a fluid; bloated
flaccid
to limp
plasmolysed
the condition of a plant cell that has lost so much water that its cytoplasm shrinks and pulls the cell membrane away from the cell wall
active transport
the movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy
facillitated diffusion
process that moves materials from high to low concentration with the help of protein channels; does not require energy
Exocytosis
Large molecules going OUT of the cell (energy required)
Endocytosis
Large molecules going INTO the cell
Phagocytosis
Cell eating
endosymbiotic theory
evolutionary theory which describes the endosymbiotic relationship between organisms and how its resulted in the evolution of eukaryotic cells sand prokaryotic cells
cell cycle
series of events that cells go through as they grow and divide
Cytokinesis
division of the cytoplasm
Interphase
Cell grows, performs its normal functions, and prepares for division; consists of G1, S, and G2 phases
Mitosis
division of nucleus to form two genetically identical daughter nuclei
Prophase
Chromosomes become visable, nuclear envelop dissolves, spindle forms
Metaphase
Chromosomes line up in the middle of the cell
Anaphase
chromosomes separate and move to opposite ends of the cell
Telephase
the chromosomes become longer, thinner, and less distinct. the nucleur membrane forms. the neocleolus reappears and cell division is nearly complete
DNA replication
the process of making a copy of DNA
sister chomatids
identical chromatids joined at a centromere
benign tumor
a mass of abnormal cells that remains at the site of origin
maligant tumor
cancerous tumour that is invasive enough to impair the functions of one of more organs
binary fission
A form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size
metstasis
the spread of cancerous cells to locations distant from their original site
Mutations
a random error in gene replication that leads to a change
Which process involves mitosis?
plant cell due to cell plate formation
Mutation causes
spontaneous generation, radiations, and certain chemicals
carcinogens
Cancer causing agents
Germline mutations are
inherited
cell theory
idea that all living things are composed of cells, cells are the basic units of structure and function in living things, and new cells are produced from existing cells
Giant Algae challenges theory (3)
complex organism
large in size
single nucleus
giant algae
atypically large / uni-nucleated cells
aseptate fungal hyphae
Challenges the idea that a cell is a single unit
Functions of Life (MR. H. GREN)
, Metabolism
Response
Homeostasis
Growth
Excretion
Nutrition