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51 Cards in this Set
- Front
- Back
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living
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a condition that is characterized by the ability of an organism to
grow metabolize respire reproduce, & adapt |
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cell theory part 1
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1.The cell is the fundamental unit of structure and function in living things.
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cell theory part 2
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2.All cells come from pre-existing cells by division.
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cell theory part 3
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3.All known living things are made up of cells.
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Organelle
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specialised part of a cell that carries out specific functions necessary for its survival (think of organs how they help humans live)
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Eukaryotic Cells
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most organelles are membrane-bound
ie. the nucleus has a double membrane Ex. animals, plants & fungi are eukaryotes |
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Prokaryotic Cells
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lack a nucleus and membrane-bound organelles
Ex. bacteria |
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Cell Membrane
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thin covering that surrounds all cells.& controls movement of materials into & out of cell
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diffusion
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random movement
higher to lower no energy needed from cell |
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osmosis
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random movement of water
higher to lower no energy needed from cell |
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active transport
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selective movement
lower to higher requires carrier molecule (energy is needed from cell) |
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cell wall (plant cells)
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Prevents cells from bursting when a plant is in a very moist environment
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Cytoplasm
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jelly-like substance
life-supporting materials (ie. water, sugars, vitamins, amino acids, …) |
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Mitochondria
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provide energy for cells by changing glucose into usable energy
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Mitochondrion
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energy centre of cell
chemical rxns that provide energy occur on the folds (cristae) of the inner membrane # of mitochondria in a cell depends on its metabolic needs (similar to chloroplast in plant cells) |
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Chloroplasts (in plant cells)
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contain chlorophyll
trap energy from Sun make glucose glucose production occurs on stacks of membranes within chloroplast |
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Ribosomes
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small, membrane-free organelles
some float in cytoplasm responsible for making proteins |
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Endoplasmic Reticulum
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network of membrane-covered channels within the cell
transport system for materials made within the cell |
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Rough Endoplasmic Reticulum
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proteins made on RER travel through channels
proteins often further processed by Golgi body / complex / apparatus |
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Vesicles
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membrane-covered sacs that form off ends of ER.
transport proteins to Golgi for processing & export from cell |
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Golgi Body
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sorts, modifies & packages proteins for transport
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Vacuoles
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membrane-bound
the cell’s storage containers |
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Nucleus
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The Control Centre
The nucleus controls the functions of the parts of a living cell, and contains the master set of instructions that determines: what each cell will become how it will function when it will grow, ÷, and die |
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Nuclear Membrane
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surrounds cell’s nucleus and protects its contents.
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Nucleolus
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membrane-free organelle that floats in nucleus. (makes ribosomes)
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Nuclear Pores
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openings in nuclear membrane
allow only certain materials into /out of nucleus ribosomes made in nucleolus leave through nuclear pores to go to cytoplasm / RER |
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DNA
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the “master set” of instructions for the cell is coded in this 2-stranded molecule that looks like a twisted ladder - a “double helix”
located in the cell’s nucleus subdivided into segments called genes |
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DNA side are made of...
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sugar (deoxyribose) & phosphate molecules
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DNA steps of ladder are made of...
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4 nitrogenous bases:
Adenine (A) Thymine (T) Cytosine (C) Guanine (G) |
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Base-Pair Rule
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A&T G&C
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Chromatin
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substance in the nucleus that contains DNA and proteins (Each strand of chromatin contains one DNA molecule)
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Chromatin During cell growth
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chromatin allows the DNA to be uncoiled & accessible, and to direct the cell while it is growing
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Chromatin During (eukaryotic) cell division
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becomes very tightly packed into structures called chromosomes
( X shaped) |
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Chromosome
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thread-like structure in the cell nucleus that carries genes
each type of organism has a characteristic # of pairs of chromosomes |
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Human Cells ALL Have
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46 chromosomes, arranged in 23 pairs in the nucleus
(female 23rd pair XX male 23rd pair XY) |
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Genes
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small segments of DNA located at specific places on a chromosome
store the information needed to produce the approximately 100 000 different proteins that your cells require to perform all of their functions one gene = one protein* can vary in length from hundreds to thousands of base pairs are “read” only when a specific protein is needed by the specific type of cell at specific times (* 1 gene, 1 polypeptide) |
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Proteins
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All of an organism’s cells contain the same genes however not all of the genes are “read” in every cell. This allows cells to be specialized so that different cell types carry out different functions.
Specialized cells group together to form tissues, and tissues group together to form organs. Proteins can be grouped into enzymes, hormones, structural proteins, blood proteins, etc. |
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Specialized Proteins
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1. Enzymes
Proteins that speed up chemical reactions that occur within cells. 2. Hormones Proteins that act as chemical messengers. Transport Proteins 3. Proteins that help move molecules across the cell membrane. |
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Specialized Proteins ex:
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nucleus receives chem. signal to make a protein
DNA message for specific protein copied into RNA RNA leaves nucleus through pore RNA message delivered to ribosome, which makes protein protein enters ER vesicle forms off ER & transports protein to Golgi |
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Gene Mutation
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a change in the specific order of the A, G, C and T bases that make up a particular gene.
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Some Types of Gene Mutation
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Deletion
1 or more of the bases is left out of the sequence Addition an extra base is added Substitution 1 base substituted for another A change at the chromosome level |
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Gene Mutation can be
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positive
negative neutral |
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Positive Mutations
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may produce proteins that benefit an organism, therefore the survival of its species.
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Neutral Mutations
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occur when errors in the base sequence of DNA appear to have no effect on the organism
the change does not increase / decrease its survival rate |
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Mutagens
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substances / factors that can cause mutations in DNA
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Correcting Mutations
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Some gene mutations can cause disease. Some ways of treating gene mutations are:
drugs surgery gene therapy …an attempt to reintroduce a working copy of the gene back into the cells of the affected individual. |
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Gene Therapy - What is Supposed to Happen
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1. Researchers determine which gene is mutated and causes the disease.
2. The healthy gene is delivered to the cell in an inactive virus. 3. The cell starts copying the healthy gene. 4. The functioning protein is used in the cell. |
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A
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adeine
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T
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thymine
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C
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cytosine
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G
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guanine
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