Lecture 1 - Intro to Cell Biology Flashcards
(44 cards)
molecules -> cells -> tissues -> organs -> organisms
cell - the basic unit of all living beings
- produces energy and uses it to build all substances necessary for life
tissues - cells that aggregate to form a specific function
organ - fully differentiated structural and functional unit in an animal that is specialized for some particular function
When did the discovery of cells occur
- after the invention of the microscope (1665)
Who are the two people that invented the microscope and which one did each of them invent
- hooke: double lens microscope (compound)
- leeuwenhoek: single lens microscope
The 3 tenants of Cell theory
- All organisms are composed of one or more cells
- The cell is the structural unit of life
- Cells can arise only by division of a pre-existing cell
Who was behind the first human cells to be cultured in vitro and what were they named
- Henrietta Lacks
- HeLa cells
- they can grow and reproduce in culture for extended periods of time
What is the difference between cell death and organismal death
cell death - death of individual cells
- normal, controlled process (apoptosis) or due to injury
- happen constantly in the body as a part of growth, repair and death
organismal death - entire organism dead
How is genetic material packed in cells
- packed in chromosomes that occupy the space of a cell nucleus (nucleoid in prokaryotes)
Do all cells contain identical copies of DNA, what happens?
- all cells contain identical copies
- become differentiated via development from a single fertilized egg
- the structure of genes allows for changes in genetic information (mutations) which lead to variation among individuals
How are cells capable of producing more of themselves
- mitosis and meiosis
mitosis: single parent cells divides to produce 2 genetically identical daughter cells
meiosis: cell division in sexually reproducing organisms that reduces the number of chromosomes in the parent cell by half - produce 4 gamete cells
How do cells acquire and utilize energy
- photosynthesis: provides fuel for all living organisms
- animal cells derive energy from the products of photosynthesis (glucose)
- cells convert glucose into ATP
metabolism
- sum total of the chemical reactions in a cell represents the cells metabolism
what do all chemical changes in the cell require
- enzymes to increase the rate at which a chemical reaction occurs
what mechanical activities do cells engage in
- cells are very active
- they transport materials, assemble and disassemble structures, and move itself from one site to another
What are mechanical changes in the cells initiated by
- changes in the shape of motor proteins
what are motor proteins
- one of many types of molecular “machines” used for mechanical activities
How do cells respond to stimuli
- they have receptors that sense environment & initiate responses
- they can alter their metabolism, moving from one place to another altering their gene expression or even committing suicide
How are cells capable of self regulation
- cells are robust and are protected from dangerous fluctuations in composition and behavior
- feedback circuits serve to return the cell to appropriate state
- they maintain a complex, ordered state which requires constant regulation
What did hans driesch find relating to self regulation
- that he could separate the first 2 or 4 cells of a sea urchin embryo and each of the isolated cells would proceed to develop into a normal embryo
How do cells evolve
- cells share many features: genetic code, plasma membrane, and ribosomes
- all living organisms evolved from a single, common ancestral that lived more than 3 billion years ago
- ancient cell referred to as LUCA
What do prokaryotes and eukaryotes share
- an identical genetic language
- a common set of metabolic pathways (glycolysis + TCA cycle)
- many common structural features
- plasma membrane, ribosomes, cytoplasm, DNA
features found in eukaryotes and not prokaryotes
- nucleus with complex chromosomes
- membrane bound organelles
- cytoskeletal filaments and motor proteins
- complex cilia and flagella
- mitosis uses a mitotic spindle to segregate chromosomes
- sexual reproduction requiring meiosis
- cellulose containing cell wall in plants
explain how eukaryotes are related to organization
- temporal and spatial arrangements of biochemical events in the cell are critical for cellular function
- cell puts an enormous amount of energy into maintaining membrane-bound domains to localize biochemical events
What are the advantages of model organisms
- relatively simple organisms
- fast generation time
- large number of offspring
- easy to manipulate in the lab
- inexpensive to breed
- conservation of many genes with humans
What are the commonly used model organisms
saccharomyces cerevisiae - yeast
mus musculus - mouse
caenorhabditis elegans - nematode worm
danio rerio - zebrafish
drosophila melanogaster - fruit fly
arabidopsis thaliana - thale cress
