Bio #1 Flashcards
the human body contains ______ bacteria cells than eukaryotic cells
more
endothelial vs. epithelial cells
Endothelial cells cover the inner surface of the blood vessel, while the epithelial cells cover the inner surface of the internal organs and the outer surface of the human body.
protein synthesis occurs in the ______
rough ER and ribosomes
proteins that will be excreted pathway:
rough ER-Smooth ER-Golgi
original cell theory
o 1. All living things are composed of cells.
o 2. The cell is the basic functional unit of life
o 3. Cells arise from preexisting cells.
o (4.) NEW: Cells carry genetic information in the form of DNA. This genetic material is passed on from parent to daughter cell
eukaryotic cells vs. prokaryotic cells
- Eukaryotic cells: nucleus enclosed in a membrane, can be unicellular or multicellular.
- Prokaryotic cells: no nucleus, always single-celled
organelles
suspended in semifluid cytosol
cytosol
the aqueous component of the cytoplasm of a cell, allows for diffusion of molecules throughout the cell
nucleus
o Surrounded by the nuclear membrane or envelope (double membrane)
o Nuclear pores: in the nuclear membrane and allow selective two-way exchange of material between the cytoplasm and the nucleus.
o Nucleolus: where ribosomal RNA (rRNA) is synthesized. Darker spot on the nucleus.
is the nuclear membrane double membrane?
yes
nuclear pores
: in the nuclear membrane and allow selective two-way exchange of material between the cytoplasm and the nucleus.
nucleolus
where ribosomal RNA (rRNA) is synthesized. Darker spot on the nucleus.
mitochondria
power plants of the cell
o Contains an outer and inner membrane.
Outer membrane: serves as a barrier between the cytosol and the inner environment of the mitochondrion.
Inner membrane: organized into cristae, contains the molecules and enzymes of the electron transport chain.
o Intermembrane space: the space between the inner and outer membranes.
o Mitochondrial matrix: the space inside the inner membrane.
o Contain some of their own genes and replicate independently of the nucleus via binary fission.
Cytoplasmic or extranuclear inheritance: the transmission of genetic material independent of the nucleus.
o Also play a role in kick-starting apoptosis.
outer membrane of mitochondria
serves as a barrier between the cytosol and the inner environment of the mitochondrion.
inner membrane of mitochondria
organized into cristae, contains the molecules and enzymes of the electron transport chain.
inter-membrane space of mitochondria
the space between the inner and outer membranes.
High concentration of protons
mitochondrial matrix
the space inside the inner membrane.
Cytoplasmic or extranuclear inheritance
mitochondria can replicate via binary fission
the transmission of genetic material independent of the nucleus
mitochondria can replicate via ____
binary fission
lysosomes
membrane bound structures containing hydrolytic enzymes that are capable of breaking down many different substrates including substances ingested by endocytosis and cellular waste products.
o Function in conjunction with endosomes, which transport, package, and sort cell material travelling to and from the membrane.
Endosomes are capable of transporting materials to the trans golgi, to the cell membrane, or to the lysosomal pathway for degradation.
o Hold in their hydrolytic enzymes. When they release their enzymes via autolysis, it directly leads to the degradation of cellular components.
endosomes
which transport, package, and sort cell material travelling to and from the membrane.
Endosomes are capable of transporting materials to the trans golgi, to the cell membrane, or to the lysosomal pathway for degradation.
endoplasmic reticulum
a series of interconnected membranes that are actually contiguous with the nuclear envelope.
o Double membrane is folded, and has a central lumen.
o Rough ER (RER): studded with ribosomes, which permit the translation of proteins destined for secretion directly into its lumen.
o Smooth ER (SER): mainly for lipid synthesis and detoxification of drugs. Transports proteins from the RER to the Golgi apparatus.
rough ER
studded with ribosomes, which permit the translation of proteins destined for secretion directly into its lumen.
smooth ER
mainly for lipid synthesis and detoxification of drugs. Transports proteins from the RER to the Golgi apparatus.
golgi apparatus
consists of stacked membrane bound sacs.
o Materials from the ER are transferred here in vesicles
o Make modifications (add carbohydrates, phosphates, and sulfates) and also attach signal sequences to things.
o Repackaged into vesicles and then sent to its correct location
peroxisomes
contain hydrogen peroxide.
o Main function is to break down very long chain fatty acids via Beta-oxidation.
o Participate in the synthesis of phospholipids and contain some of the enzymes involved in the pentose-phosphate pathway.
cytoskeleton
provides structure to the cell and helps it to maintain its shape.
o Also used for transport of materials around the cell
what are the 3 types of cytoskeleton
microfilaments
microtubules
intermediate filaments
microfilaments
made up of solid polymerized rods of actin.
The actin filaments are organized into bundles and networks and are resistant to compression and fracture.
Interact with myosin to generate force for movement.
Play a role in cytokinesis, forming the cleavage furrow, actin filaments contract and pinch off the connection between the two daughter cells.
what cytoskeletal component is involved in movement, muscle contraction
actin
microtubules
hollow polymers of tubulin proteins.
Provide pathways for motor proteins kinesin and dynein to carry vesicles.
Cilia and flagella are composed of MT
• Cilia: projections from a cell that are primarily involved in the movement of materials along the surface of the cells.
o Ex: movement of mucus in the respiratory tract.
• Flagella: structures involved in the movement of the cell itself
o Ex: sperm through the reproductive tract.
• The two share the same structure, 9 pairs of MT on the outer ring and 2 MT in the center: 9+2 structure
o Only seen in eukaryotic organelles of motility.
Centrioles: found in a region of the cell called the centrosome.
• The organizing centers for MT and are structured as nine triplets of MT with a hollow center.
• Migrate to opposite sides of the dividing cell during mitosis and organize the mitotic spindle.
o The MT emanate from them and attach to chromosomes via complexes called kinetochores
kinesin, myosin, dynein
actin: myosin
tubulin: kinesin and dynein
what are cilia and flagella composed of
microtubulues
cilia
projections from a cell that are primarily involved in the movement of materials along the surface of the cells.
o Ex: movement of mucus in the respiratory tract.
9 pairs of MT on the outer ring and 2 MT in the center: 9+2 structure
o Only seen in eukaryotic organelles of motility.
flagella
structures involved in the movement of the cell itself
o Ex: sperm through the reproductive tract.
9 pairs of MT on the outer ring and 2 MT in the center: 9+2 structure
o Only seen in eukaryotic organelles of motility.
centrioles
found in a region of the cell called the centrosome.
• The organizing centers for MT and are structured as nine triplets of MT with a hollow center.
• Migrate to opposite sides of the dividing cell during mitosis and organize the mitotic spindle.
o The MT emanate from them and attach to chromosomes via complexes called kinetochores.
intermediate filaments
diverse group of filamentous proteins, which includes keratin, desmin vimentin, and lamins.
Involved in cell-cell adhesion or maintenance of the integrity of the cytoskeleton.
Able to withstand a tremendous amount of tension.
what are the 4 different types of tissue?
epithelial, connective, muscle, and nervous
epithelial tissue
cover the body and line its cavities, providing a means for protection against pathogen invasion and desiccation.
Tightly joined to each other and to an underlying layer of connective tissue known as the basement membrane.
Diverse role depending on the organ.
• In most organs they constitute the parenchyma: the functional parts of the organ.
Polarized: one side faces a lumen of the organ or the outside world while the other side interacts with underlying blood vessels and structural cells.
Classified based on the number of layers and their shape:
• Simple epithelia: one layer of cells
• Stratified epithelia: have multiple layers
• Pseudostratified epithelia: appear to have multiple layers due to differences in cell height but in reality are only one layer.
• Cuboidal: cells are cube-shaped
• Columnar: cells are long and thin
• Squamous: cells are flat and scale-like.
basement membrane
underlying layer of connective tissue under epithelial tissue
simple epithelia
one layer of cells
stratified epithelia
have multiple layers
pseudo-stratified epithelia
appear to have multiple layers due to differences in cell height but in reality are only one layer.
cuboidal
cells are cube-shaped
columnar
cells are long and thin
squamous
cells are flat and scale-like.
connective tissue
supports the body and provides a framework for the epithelial cells to carry out their functions.
Contribute to the stroma or support structure of the organ.
Ex: bone, cartilage, tendons, ligaments, adipose tissue, and blood are all connective tissues.
Most cells in connective tissues produce and secrete materials such as collagen and elastin to form the extracellular matrix.
stroma
support system of the organ
connective tissue
prokaryotes
o Include all bacteria
o Do not contain any membrane bound organelles
o Genetic material is organized into a single circular molecule of DNA concentrated into an area of the cell called the nucleoid region.
what are the prokaryotic domains?
archaea and bacteria
archaea
Single-celled organisms that are visually similar to bacteria, but contain genes and several metabolic pathways that are more similar to eukaryotes than bacteria.
Once classified as extremophiles: able to live in harsh environments
Ability to use alternative energy sources.
Live in the human body.
To eukaryotes:
• Similar: start translation with methionine, contain similar RNA polymerases, and associate DNA with histones.
• Different: single circular chromosome, divide by binary fission or budding, and have similar structure to bacteria.
bacteria
All contain a cell membrane and cytoplasm, and some have flagella or fimbriae (similar to cilia).
Flagella and ribosome are very different than eukaryotic and are targeted by antibiotics.
Some are mutualistic symbiotes: both humans and bacteria benefit from the relationship.
• Ex: some bacteria in the gut
Others are pathogens or parasites: they provide no advantage or benefit to the host, but rather cause disease.
• Can live inside or outside of cells.
extremophiles
able to live in hard environments
how are archaea similar and dissimilar to eukaryotes
- Similar: start translation with methionine, contain similar RNA polymerases, and associate DNA with histones.
- Different: single circular chromosome, divide by binary fission or budding, and have similar structure to bacteria.
bacteria and eukaryotes are different?
- Flagella and ribosome are very different than eukaryotic and are targeted by antibiotics.