Cell Theory and Cell Structure Flashcards
What traits do all living things exhibit?
- Order
- Metabolism
- Homeostasis
- Response to Stimuli
- Reproduction
- Growth and Development
- Evolutionary Adaptation
What is order?
the structural organization and molecular complexity
What is metabolism?
transforming chemicals and derive energy to generate usable components
What is homeostasis?
ability to regulate itself, cells can regulate and respond
What is the response to stimuli?
dynamic changes in response to environmental stimuli
What is growth and development
mature and interact with the environment
What is evolutionary adaptation?
the change over time in response to stimuli
What is a cell?
The simplest unit of life and can replicate
Who found cells and when?
Robert Hooke in da year of 1665
What is the cell theory?
1) all organisms made of cells
2) cells are the smallest living things
3) cells arise only from pre-existing cells
What domains are prokaryotes?
Bacteria and Archaea
What are common features of prokaryotic cells?
unicellular, no nucleus, has a cell wall
What are viruses?
non-living, obligate intracellular parasites, ARE NOT CELLS
What domains are eukaryotes?
protists, fungi, animals, and plants
What are common features of eukaryotic cells?
uni- or multicellular, have nucleus, have organelles, some have cell walls.
How much is a micrometer?
one millionth of a meter (10^-6)
How much is a nanometer?
one billionth of a meter (10^-9)
What are the limitations to cell size?
- genetic regulation
- suface to area volume
What are some aspects of genetic regulation that limit cell size?
translation requires mRNA, tRNA, and ribosome to find each other and if the cell is too big it is harder to find
What is the cell size difference between prokaryotes and eukaryotes?
prokaryotic cells are 1/10 to 1/100 micrometers of the size of eukaryotic cells
What is the cell size of viruses?
1/10 to 1/100 micrometers of the size of prokaryotic cells
Differences between archaea and bacteria?
1) No peptidoglycan (cell wall structure)
2) Use of histones (like Euk)
3) Use of methionine (like Euk)
4) Extremophile tendencies
What makes a cell prokaryotic?
1) have no true nucleus
2) reproduce asexually (binary fission)
3) have circular chromosomes
4) are unicellular
What is the glycocalyx? & what are the types of glycocalyx?
PROKARYOTIC CELL
material surrounding the cell, often a thick sticky sugar coat
2 types are capsule & slime layer
Which type of glycocalyx is more stable?
capsule
What is the flagellum?
PROKARYOTIC CELL
long filament(s) used for taxis (stimulus directed movement)
What is the fimbriae?
PROKARYOTIC CELL
small hair-like projections used for attachment to surfaces
What is the pili?
PROKARYOTIC CELL
long hair-like projection for motility, also DNA transfer (conjugation)
What is the cell wall?
semi-rigid structure that maintains cell shape
-Lies immediately below the glycocalyx
-Provides the bacteria with structure/protection
What is the meaning of gram positive cell wall composition?
cell wall made of thick layer of peptidoglycan (cross-linked sugars)
What is the meaning of gram negative cell wall composition?
cell wall made of a thin layer of peptidoglycan, have an outer layer of lipopolysaccharides (LPS) (membrane layer loaded with sugar molecules)
How might the differences in gram positive and gram negative cell wall compositions effect susceptibility to antibiotics like penicillin?
gram positive is antibiotic resistant as the antibiotic can move quicker in and out through the cell.
What are the membranes and cytoplasm in a cell?
plasma membrane, cytoplasm, and cytosol
What is the cytoplasm and what is in it?
Everything inside the cell
Including:
- cytosol
- ribosomes
- genetic material
What is cytosol?
cytoplasmic fluid w/ nutrients, salts, and proteins
What are plasmids?
small circular DNA pieces w/ non-essential genes in prokaryotic cells
What are nucleoids?
double-stranded circular chromosome (DNA) w/ essential genes
Where is DNA found in a prokaryotic cell?
the nucleotides and plasmids
What is the cell wall in eukaryotes?
a rigid outer cell boundary present in plants, fungi, and many protists (provides structure and stability)
what does a cell wall look like in plants?
1 and 2 prime cell walls made of cellulose
what does the cell wall look like in fungi?
there is generally a single cell wall made of chitin
what does the cell wall look like in protists?
there is generally a single cell wall made of a variety of stuff
Where is the cytoplasm in a eukaryotic cell?
in the intracellular space between the plasma membrane and the nucleus
What is in the cytoplasm in an eukaryotic cell?
- cytoplasm
- proteins and ribosomes
- organelles
- inclusions (glycogen granules, pigments, lipid droplets, vacuoles crystals)
What is the cytosol in an eukaryotic cell?
cytoplasmic fluid w/ nutrients, sugars, salts, and proteins
what cells have ribosomes?
ALL CELLS
What are the two types of ribosomes?
free & membrane bound
What are ribosomes?
site of protein synthesis (translation)
what are free ribosomes?
synthesize soluble proteins for cytosol or other organelles
What are membrane-bound ribosomes?
bound to ER, synthesize proteins to be trafficked
What is the endomembrane system?
the membrane associated structures of the cell that allow
- intracellular trafficking
- compartmentalizing function
What is the nucleus?
contains genomic DNA (chromatin)
What are the 6 major components of the end-membrane system?
- nucleus
- endoplasmic reticulum
- Golgi apparatus
- lysosomes
- vesicles
- cell membrane
What is the nucleolus?
the dark region of the nucleus associated with forming rRNA
What is the nuclear envelope?
a membrane bilayer surrounding the nucleus which contains nuclear pores to regulate what gets in and out
What is the nucleoplasm?
the inner contents of the nucleus (nucleus cytoplasm)
What is the nuclear lamina?
dense fibrous protein network provides structure to the nucleus facilitates its disassembly during cell division
What is the nuclear matrix?
network of nuclear fibers within the nucleus; scaffold to establish designated chromosome territories
What is the endoplasmic reticulum?
network of membrane sacs which synthesize and store proteins and other molecules it is connected to the nuclear envelope
What are the 2 types of ERs?
rough ER and smooth ER
What is the rough ER?
an organelle involved in the synthesis and modification of proteins for trafficking of the cell
**ROUGH W/ RIBOSOMES
What is the smooth ER?
site of lipid (fats and steroids) synthesis, Ca ion storage, some carb. metabolism, and detoxification
What is the Golgi apparatus?
the network of flattened membrane sacs (saccule)
What does the Golgi apparatus do?
- protein and lipid modification
- transport throughout the cell in vesicles
What are lysomes and what do they do?
small membrane-bound vesicles produced by the Golgi
What do lysomes do?
- contain acids and hydrolytic enzymes
- breaks down/recycles molecules
- same process used to kill bacteria
What is the plasma membrane?
a bilayer of phospholipids which controls movement of substances in and out of the cell
what are the primary function of the plasma membrane?
- protect the cell
- maintain ion concentrations (osmotic balance) of various substances
- selectively permeable (allows some molecules in, others are kept out)
- cell-to-cell communication
- cell adhesion
What is the structure of the mitochondria?
Double membraned structure where the inner membrane is highly folded into Cristae to increase inner surface area.
What is the matrix in the mitochondria?
the inner most space, most reactions take place here
What are the chloroplasts?
double membrane bound and used for photosynthesis
- have own ribosomes and DNA
- contain chlorophyll (green pigment)
What are parts of the chloroplast?
thylakoid (flattened sacs), grana (stacks of thylakoid), stroma (inner part of chloroplast)
Whats the relationship between prokaryotic and eukaryotic cells?
Eukaryotic cells evolved from prokaryotic cells because eukaryotic organelles resembles prokaryotic cells
What are cytoskeletal structures?
- microfilaments
- intermediate filaments
- microtubules
- centrioles and centrosomes
What is the flagella?
long hair-like projections used for motility (different composition for prokaryotic/eukaryotic flagella)
What is cilia?
Tiny hairlike projections used to propel substances along the surface of the tissue and for motility(Like in your throat/esophogus)
What is microvilli?
minute, fingerlike extensions of plasma membrane
- increase SA for absorption
What are the 4 types of tissues in animal and plant cells?
- epithelium
- connective
- muscle
- nervous
how is epithelium tissue used?
body linings and surfaces
Are plant and animal tissues similar?
no, they evolved differently
what does connective tissue do?
exhibit secreted extracellular matrix
what are the two types of cell walls in plants?
primary and secondary
what is the primary cell wall?
produced during cell growth
what is the secondary cell wall
thickened more rigid structure (different molecular structure)
What is the extracellular matrix made of in animal cells?
proteoglycans (protein core surrounded by glycosaminoglycans aka GAGs)
What forms proteoglycans with GAGs in animal cells?
collagen and elastin
What is epithelial tissue made of?
mix of collagen and laminins
What does connective tissue excrete?
large amounts of ECM
What are the 3 types of junctions in animal cells?
tight junctions
desmosomes
gap junctions
What do tight junctions do?
use proteins (Claudius and occludins) to form an impermeable barrier
what do anchoring junctions and desmosomes do?
use cadherins (calcium0dependent adhesion proteins) for support
- shape change
What do gap junctions do?
use connexions to permit ion flow by forming channels between cells
