Cells and Replication Flashcards
what is cell theory?
the cell is an organism’s basic unit of structure and function
- all organisms are made of cells
- all cells come from pre-existing cells
what are the three domain classifications of organisms?
bacteria, archaea, eukarya
archaea look like ______ on the outside and ______ on the inside
bacteria, eukarya
almost all bacteria/prokaryotes are ____-celled
single
almost all eukarya are ____-celled
multi
basic features of all cells
- enclosed by a dynamic [plasma membrane] that regulates the passage of materials between the cell and its surroundings
- contain a semifluid substance called [cytosol]
- use [DNA] as their genetic info
- have [ribosomes] that make proteins
eukaryotic cell vs. prokaryotic cell
eukaryotic cell (animals, plants, fungi, and protists): membrane-enclosed organelles, nucleus, larger, more complex
prokaryotic cell (bacteria, archaea): no membrane-enclosed organelles, no nucleus, smaller, less complex
what is the organelle in plant cells called?
chloroplast (converts sunlight into sugar)
do both plant and animal cells have mitochondria?
yes
why is plant tissue stronger than animal tissue?
because of their surrounding cell wall
dynamic biological membrane
- dual bilayer of phospholipids
- proteins formed in pores
- turn on or off certain genes based on environmental stimuli
- barrier and start of signaling cascade
where are genes turned on and off?
in nucleus
nucleus
contains chromosomes, made of chromatin (DNA and proteins)
- contains nucleoli where ribosomal subunits are made
- pores regulate entry and exit of materials
ribosomes
protein synthesis
endoplasmic reticulum
smooth ER: synthesis of lipids, metabolism of carbohydrates, Ca2+ storage, detoxification of drugs and poisons
rough ER: aids in synthesis of secretory proteins from bound ribosomes; adds carbohydrates to proteins; produces new membrane
Golgi apparatus
modification of proteins, carbohydrates on proteins, and phospholipids; synthesis of polysaccharides; sorting of Golgi products, which are then released in vesicles
lysosome
breakdown of ingested substances, cell macromolecules, and damaged organelles for recycling
vacuole
(mostly in plants) digestion, storage, waste disposal, water balance, cell growth, and protection
mitochondrion function
cellular respiration
chloroplasts function
(in plants) photosynthesis
peroxisome
oxidative organelles which breaks down toxic molecules
nucleus contains ___________
most of cell’s DNA
additional genes, not in nucleus, are in _________ in and __________
mitochondria, chloroplasts
most of the cell’s tRNAs are produced in the __________
mitochondrion
genome
the complete set of genes or genetic material [DNA in an organism’s nucleus and mitochondria (and chloroplasts)] present in a cell or organism
genomics
the large scale study of sets of genes within and between species
chromatin
complex of DNA and proteins
genes found on
chromosomes
in eukaryotes, during cell division, chromatin condenses to form discrete ____________
chromosomes
human genome is diploid or haploid
diploid (contains two complete sets of chromosomes, one from each parent, 23 from each parent)
normal human karyotype
23 from each parent, 22 same pairs, last pair is either XX (female) or XY (male)
gene is unit of ___________
inheritance
what is a gene
a sequence of nucleotides on DNA that provide cells with with the info needed to a produce a specific protein (or for functional RNA molecules)
how many genes are on each chromosome?
hundreds - thousands of genes
one of copy of the human genome consists of _____________
approximately 3 billion base pairs of DNA, distributed across 23 pairs of chromosomes
how many nucleotides in genes?
about 1000-4000 nucleotides per gene