lesson 2 Flashcards
common features between prokaryotes and eukaryotes…
- plasma membrane similar construction
- genetic info using identical code
- some shared metabolic pathways ex. glycolysis
- similar mechanism to make ATP
- similar mechanism for photosynthesis
- similar mechanism for synthesizing and creating inserted membrane proteins
- similar proteosomes (protein digesting structures)
- some similarities in cytoskeletal features
what is the basic property of all cells?
cells are small
what are the three reasons a cell has to be so tiny?
- limited genetic information
- surface area: volume - a cell can only be so big before its membrane will not work
- diffusion - all things move through the process of diffusion, a large cell would take too long to diffuse things through
micrometers info
- there are 1000 microns in 1 mm or 10 to the -6 m
- most eukaryotic cells are between 10-30 microns
- most prokaryotic cells are about 1-5 microns
info about nanometers?
units = nm
- there are 1000 nm in 1 micron or 10 to the -9
- cell components measured in either microns or nanometers
angstrom info
- there are 10 angstroms in a nm or 10 to the -10
- approximately diameter of a hydrogen atom
- used to describe macromolecules
sizes
ribosome = 25-30nm wide
membrane = 7-8nm
microtubule = 25nm
microfilament= 7nm
DNA helix = 2nm
what microscopes are used when?
light microscopes look at small molecules from 1mm-about 100nm
electron microscopes look at super small molecules from 100 microns to 0.1nm
cell biology is… and why?
it is reductionist
- hard to know what is going in inside cells
- all kinds of amazing techniques
- indirect observation
- look at the parts to explain the whole
cells are highly…
complex and organized
- many moving but connected parts, so therefore LOW tolerance for errors
what are the three basics about cells?
- they possess a genetic program and means to use it
- they are capable of producing more of themselves
- they acquire and utilize energy
photosynthesis summary for autotrophs
- they convert the sun’s energy into chemical energy (mostly in the form of glucose) via photosynthesis
photosynthesis for heterotrophs
- they need to get their chemical energy from the organic molecules that they eat
- humans are heterotrophs
all organisms…
convert the chemical energy in organic molecules into ATP via cellular respiration
what is metabolism
all the chemical reactions occurring in a cell - EVERYTHING
what is a metabolic reaction
the chemical reactions in the body’s cells that change food into energy - one change in the chemicals in the metabolites
what is a single metabolic pathway
a series of connected chemical reactions that feed one another
what are four more statements about cells?
- cells engage in mechanical activities, white blood cells are sent to infection spots
- cells are able to respond to stimuli
- cells are capable of self-regulation , regulate environment so it is what they need
- cells evolve
where did the first cell come from? short history
- earth formed 4.6 bya
- first protocell (Last Universal Common Ancestor) 3.5 bya
- first prokaryotes (early photosynthetic bacteria) 3 bya
- cyanobacteria (later photosynthetic bacteria) this led to the Great Oxygenation Event 2.4 bya
- first single celled eukaryotes (primitive nucleated cells) 2 bya
- mitochondria and chloroplasts 1.25 bya
- multicellularity 1 bya
- humans 200 000 years ago
is spontaneous synthesis of biological materials even possible? 1952
Harold Urey and Stanley Miller
- mixed water vapour, methane, ammonia, hydrogen gasses in sealed glass apparatus (recreated early earth atmosphere)
- one week later = organic compounds, including amino acids and carbohydrates collected
- so YES these conditions could lead to the generation of organic compounds necessary for spontaneous life
what is LUCA
- we don’t actually know what LUCA was but we do know that cells had to come from somewhere and despite cells having different properties, all cells had to have a common ancestor ex eukaryotes and prokaryotes have to be connected somewhere
- all life came from LUCA
endosymbiont theory
membrane of larger cell tries to “eat” a smaller cell but rather than be digested they combine together to create a double membrane molecule
what is a proteukaryote?
anaerobic heterotrophic cells
anaerobic means they derived their energy from food matter without employing molecular oxygen
heterotrophic meaning unable to synthesize organic compounds from inorganic precursors (such as water) but instead had to obtain pre-formed organic compounds from their environment
aerobic prokaryotes derive their energy from where?
from food matter employing molecular energy
