Unit 1 Flashcards
What does cell theory state?
All living organisms are made up of cells
Cells are the smallest unit of life
existing cells have come from other cells
In a prokaryote is DNA in envelope?
No it’s free
What’s a prokaryote ?
single celled organism w no nucleus
in Eukaryote is DNA in envelope?
yes in nucleus
in a prokaryote is DNA naked or attached to proteins?
naked, it’s in the nucleoid
in eukaryote is dna naked or attached to proteins?
the dna is attached to protein in nucleus
in prokaryote is DNA circular or linear?
1 circular chromosome
in eukaryote is is dna circular or linear?
many linear chromosomes
in prokaryote is mitochondria present?
no
in eukaryote is the mitochondria present?
yes
in prokaryotic cells what is the size of ribosomes?
70s
in eukaryotic cells what is the size of ribosomes ?
80s
eukaryotic organelles with double membrane
mitochondria, nucleus, chloroplast
4 differences between plant and animal cells
Plants have cell wall, plants have large central vacuole, plants have plastids, and plants do not have centrioles unlike animals.
differences is fungal cells
fungal cells have cell wall and vacuole but no plastids or centrioles
exceptions to cell theory
red blood cells: don’t have nucleus
phloem sieve tube elements: no nucleus- moves sugar
skeletal muscle: connected to skeleton,fusion of muscle cells, has many nuclei
aseptate fungal hyphae- anchor fungus, many nuclei
how many layers in cell membrane?
2, phospholipid bilayer
phospholipids are hydrophobic and hydrophilic. what is this called?
amphipathic
which part of a phospholipid is hydrophobic?
the lipid tails
which part of phospholipid is hydrophilic?
the head
developments in microscopy
freeze fracture electron microscopes- breaks apart frozen image -see image up to 1 mill x bigger
fluorescent stains- uses uv and ir to add color and see certain things
cryogenic electron microscopy- froze, rotated. sees protein shapes
resolution definition
the ability to tell that 2 images aren’t one
magnification formula
image/ actual
actual magnification
objective lense x eyepiece
structures all cells have
plasma
cytoplasm
dna
structures all cells have
plasma
cytoplasm
dna
lysis definition
breaks apart- death of cell
where is metabolism
cytoplasm
what is the prokaryotic cell wall made of
peptidoglycan
what are the dark spots on prokaryotic micrograph
proteins
prokaryotic nucleoid region
where dna is
light region
no proteins
requirements of eukaryotic cell
multicellular, has nucleus, or both
eukaryotic nucleus
round, large, has protein, 2 membranes, protects
eukaryotic smooth endoplasmic reticulum
makes lipids and other molecules
eukaryotic rough er
ribosomes attached
connected tubes for easy transport(cisterna)
eukaryotic Golgi Apparatus
not connected tubes & cisterna that takes proteins from rough ER
changes fixed proteins because of separated tubes
eukaryotic lysosomes
single membrane spheres
breaks down proteins, wastes
eukaryotic mitochondria
makes energy in form of atp by cell respiration
2 membranes- the 2nd has folds to add surface area for cell respiration
eukaryotic free ribosomes
80s
makes proteins for cell itself
eukaryotic chloroplasts
only plants
photosynthesis
eukaryotic vacuoles and vesicles
storage and transport
vesicles take ribosomes from ER to golgi
vacuoles mainly used for storing water
mainly empty
eukaryotic vacuoles and vesicles
storage and transport
vesicles take ribosomes from er to golgi
vacuoles mainly used for storing water
mainly empty
eukaryotic cilia & flagella
move cell around
microtubules, centrioles, & cytoskeleton
microtubules make up the centrioles and is held together by proteins, which makes up cytoskeleton
what is homeostasis
maintenance of internal stable condition- keeps cell alive
what is metabolism
responsible for all chemical reactions
processes of life for all organisms
homeostasis
chemical reactions
nutrition
growth
respond to stimuli
reproduction
which eukaryotic groups have plastids
plants
which eukaryotic groups have cell wall
plants and fungi
which eukaryotic groups have vacuoles
plants-large central & fungi. animals can have some small
which eukaryotic groups have centrioles
animals
which eukaryotic groups have undulipodia(moves cell )
animals, plants have a few and fungi have few
hydrophobic
doesn’t mix with water- non polar
hydrophilic
does mix with water- polar
how does the phospholipid bilayer arrange
it’s automatic. the head is attracted to water and the tails to each other. the outside layer of heads are attracted to the outside
how thick is the cell membrane
10 nanometers - .01mm
what kind of molecules get through the cell membrane easier
non polar ones. ex: oxygen and carbon dioxide
where are hydrophobic molecules are attracted to in the membrane
the inside
where are hydrophilic molecules are attracted to in the membrane
the outside
high energy molecules means what?
not bonding, opposite polarity
what is simple diffusion
molecule spread out bc of random motion
high to low concentration either down gradient or with it
concentration gradient
different concentrations
passive meaning
doesn’t require energy- diffusion
simple diffusion in cell membrane
only small non polar molecules can get across easily. example: oxygen in the cornea
2 types of proteins in membranes
integral: all the way across
peripheral: either on top or bottom
example of cell with not a lot of proteins
neuron cell
how does cell activity impact proteins
more active=more proteins
aquaporins
membrane proteins that allows water through- integral
osmosis
when water enters or leaves cell
facilitated diffusion
when molecules move down concentration gradient but using membrane protein
facilitated diffusion
when molecules move down concentration gradient but using membrane protein
channeled protein
allows molecules in & out. its flows(no energy required) specific structure
active transport
uses energy, against concentration gradient. pumped
low to high
one way
uses membrane protein
selective permeability
form and function determines what gets in and out. its specific
glycoproteins
made from carbohydrates and a protein
protein is embedded and carb sticks off
protein is non polar and carb is polar
glycolipid
lipid is embedded and carb sticks off
functions of glycolipids and glycoproteins
recognizes other cells, determines if good or bad. cell to cell fusion- gets cells to stick together to form tissues
fluid mosaic model
best model of membrane. fluid- moves cell
mosaic- different proteins and fluids
prokaryotes: membrane bound organelles?
prokaryotes don’t have membrane bound organelles. a good thing is that it’s efficient since everything is in one place. and bad thing is that there’s no separation of processes. there’s interference
eukaryotes: membrane bound organelles?
eukaryotes do have membrane bound organelles. this uses compartmentalization
compartmentalization
keeping things separate.
- enzymes and substrates in small area(high concentration)
-keeps harmful substances away from each other
-separation of different pH
-movement
-concentration gradient
polarity meaning
partially negative charged and partially positive charged=attracted
solute
being dissolved
solvent
doing the dissolving
concentration meaning
amount of solute in solution
cytoplasm and osmosis
high solute means less water. the high solute will want to go where there is less solute and the low water will want to go where there is high water
hypotonic
lower concentration than other solution.
water moves away
causes cell to swell if solution is outside
hypertonic
higher concentration
water goes towards
shrinks cell
isotonic
same concentrations
water goes both ways at same rate
water crossing cell membrane
more often than the solute
appears to be low to high but it’s really high to low
what organelles do eukaryotic and prokaryotic cells both have?
plasma membrane, cytoplasm, and ribosomes
what are the 4 components of cell membranes?
phospholipid
protein
carbohydrate
cholesterol
functions of the glycoproteins and glycolipids
cell to cell recognition
act as receptor sites for chemical signals
acting as binding of cells into tissues
what will happen if a typical animal cell is placed in a hypotonic solution?
the cell will burst because of the large entry of water by osmosis
what will happen if an animal cell is placed in a hypertonic solution?
the cell will shrink due to losing water from cytoplasm
what is a stem cell?
an undifferentiated cell with potential to divide and differentiate
is osmosis high to low concentration or low to high concentration?
osmosis is high to low concentration with water, but if it’s with a solute it is low to high concentration.
What are some uses of an isotonic solution?
contact solution, transporting organs, liquid in IV’s
Example sentence: An isotonic solution is commonly used in contact lens solution to match the osmotic pressure of the eye’s natural fluids.
What is meant by “turgidity”?
Turgidity means that the cell is full of water
Example sentence: Plant cells rely on turgidity to maintain their structure and support.
When a concentrated solution of glucose is separated from a dilute solution of glucose by a partially permeable membrane, determine which solution will show a net gain of water molecules.
The water will go towards the concentrated solution of glucose. The glucose solution will have a net gain.
Example sentence: This process is known as osmosis and is crucial for maintaining proper water balance in cells.
Explain, using your knowledge of osmosis, what happens to a fungal spore that starts to grow after landing on jam made from fruit and its own weight of sucrose.
The fungal spore is hypotonic and has a high amount of water so the water is moving away and the concentration in the jam is moving inside the fungal spore.
Example sentence: Osmosis plays a role in nutrient absorption and growth in various organisms.
State three sources where stem cells can be obtained.
Bone marrow, hair, nails
Example sentence: Bone marrow is a common source of adult stem cells used in medical treatments.
Distinguish between totipotent, pluripotent, and multipotent.
Totipotent- most potential to differentiate, zygotes or early embryos
Pluripotent- potential to differentiate, later embryos or developing fetuses
Multipotent- quite limited potential, already mostly differentiated
Example sentence: Understanding the different types of stem cells is crucial for their therapeutic applications.
State two significant features about stem cells that make them suitable for stem cell therapy.
They haven’t differentiated yet
They can divide
Example sentence: The ability of stem cells to differentiate and replace damaged tissues is the basis of stem cell therapy.
What happens to the surface area to volume ratio as a cell increases in size?
The ratio gets smaller
Example sentence: Cells need to maintain a high surface area to volume ratio for efficient nutrient exchange and waste removal.
What is the function of the surface area of a cell?
Cells want more surface area for a small amount of volume so that there is easier transport of materials and for sped up chemical reactions.
Example sentence: Microvilli on the surface of cells increase the surface area for absorption of nutrients.
Describe some examples of how certain cells’ sizes are directly related to their function.
White blood cells are small so they can get places easily to fight antibodies
Sperm cells are small to allow for more of them
Example sentence: The size and shape of cells are intricately linked to their specialized functions in the body.
reasons for new cells
-cell maintenance- replacing cells
-to grow- add cells
-reproduction- single cell organisms reproduce by cell division
what is cytokinesis
the actual process of cell division
cytokinesis in animals
-Cleavage Furrow-center where its being pulled
-Actin and Myosin-proteins that pull cell membrane to cleavage furrow-pinches cell
cytokinesis in plants
-Cell Wall is rigid and doesn’t allow pinch
- Vesicicles Full Of proteins Move to center Of CelI and Fuse together
- Pectins- build new cell Wall
- Lamella- pre cell wall
unequal cytokinesis
Both new cells still get same
DNA
ex: budding in yeast
- Eukaryotes
- buds off parent
- don’t have to grow first-duplicate Fast
-many times
ex 2: Oogenesis: production of egg cell
- Only 1 cell
- polar body
-end with 1 large cell and 2 dissolved polar bodies
examples of unequal cytokinesis
budding in yeast
-eukaryotes
-buds off parent
-doesn’t have to grow first so they duplicate fast many times
Oogenesis
-production of egg cell
-only 1 cell
-ends with 1 large cell and 2 dissolved polar bodies
examples of unequal cytokinesis
budding in yeast
-eukaryotes
-buds off parent
-doesn’t have to grow first so they duplicate fast many times
Oogenesis
-production of egg cell
-only 1 cell
-ends with 1 large cell and 2 dissolved polar bodies
when does the nucleus divide
the nucleus has to divide with cytoplasm first
example of division without nucleus
red blood cells- divide quickly
2 types of nuclear division
- mitosis
-making identical copies
- same number of chromosomes it started with
-tissue production and sexual reproduction - meiosis
-reproductive cells
-number of chromosomes cut in half
-not identical copies-increases genetic diversity
when should dna duplicate
dna must duplicate before nuclear division
dna replication
-chromosomes become double stranded
-duplicant is connected to original-same number of chromosomes
-amount of dna has doubled
-sister chromatids are attached together in chromosome held together by protein called cohesin
-cohesin is cut and sisters are separated
-single stranded chromosomes again
why are chromosomes condensed first in nuclear division
makes it easier to move
histone protein in condensing of chromosomes
dna wraps around bundle of histones which then wraps around that bundle and keeps compounding until very dense- called supercoiling
microtubules in cell division
attach to cohesin and pull it apart to opposite sides
microtubule organizing center
proteins that organize and pull apart chromosomes
phases of mitosis
interphase: when dna duplicates-single to double stranded
prophase: chromosomes condense, mtoc forms, nucleus dissolves
metaphase:moved to middle so can be pulled apart evenly
anaphase: chromosomes pulled apart to opposite sides
telophase: chromosomes uncondense, mtoc dissolves, 2 nuclei reform-1 around both sets of chromosomes
