Download 3. Cells (Parts and functions, Processes) Cells are the building

3. Cells (Parts and functions, Processes)
Cells are the building blocks of all living things.
Prokaryotes: single cells, no nucleus or membrane bound organelles
Eukaryotes: Larger cells. Can be single or multicellular. Contains nucleus and
membrane bound organelles.
Cells are about 70% water.
Cell organelles
5
6
Cell Membranes
Passive Transport
No energy required by the cell
Diffusion and Osmosis
Diffusion is the movement of molecules from high to
low concentrations.
Osmosis is the diffusion of water through a selectively permeable
membrane.
Active Transport
Requires energy. Moves against concentration gradient or no concentration
gradient required.
7
4. DNA & RNA
Stores information to build proteins.
Pioneer work done by Watson, Crick, Wilkins, and Franklin
Double Helix, very stable
Adenine combines with Thymine
Cystosine combines with Guanine
Hydrogen bonds hold strands together
DNA Replication
Copying of complete genome during S-phase of cell cycle.
Enzymes are needed to initiate and continue replication.
helicase, polymerase, ligase
Transcription
First step in Protein Synthesis
Occurs in nucleus of eukaryote: cytoplasm of prokaryote
mRNA copy made of coding strand of DNA
RNA polymerase
mRNA transferred to ribosome for translation
8
5. Mitosis, Meiosis
Cell Cycle
G1: growth, production of new organelles
S: copying of DNA
G2: more growth and organelle production
M: mitosis, prophase, metaphase, anaphase, telophase
Cytokinesis: separation/division of cell into two
identical cells
Mitosis Phase
Prophase - chromosomes condense and form sister chromatids
Metaphase-chromosomes line up in the middle of cell; sister chromatids straddle metaphase
plate in middle of cell
Anaphase- Paired centromeres of each chromosome separate and the individual sister
chromatids move to opposite poles.
9
Telophase: Nuclei begin to form in each cell, coils are less tight, membrane begins pinching
in.
Cytokinesis: not a phase of mitosis, separation of 1 cell into two identical cells.
6. Heredity and Genetics
-The offspring inherits from their parents
-Chromosomes contain genetic information containing of genes that are coded for proteins
-Somatic Cells: contain all cells except sex cells, have 23 pairs of chromosomes, also
known as autosomes
-Pair of sex chromosomes determine gender of offspring
7. Mutations
● A mutation is a permanent change in the DNA sequence of a gene. Mutations in a gene's DNA
sequence can alter the amino acid sequence of
the protein encoded by the gene.
● The four types of mutations are:
○ Substitution-a mutation that exchanges one base for another (i.e., a change in a single
"chemical letter" such as switching an A to a G).
○ Insertion-mutations in which extra base pairs are inserted into a new place in the
DNA.
○ Deletion- a mutation where sections of the DNA have been removed
○ Frameshift- a mutation that occurs when a Deletion or Insertion occurs. Because
codons are grouped into 3, when any of the above mutations occurs, the acids are
grouped into new codons
10