Flashcards in Cell Structures and Functions Deck (125):
chromatin phase-loose DNA
chromosome phase-tightly packed DNA
Has Pores, protects nucleus, Double Membrane (phospholipids) (one side is hydrophilic and one side is hydrophobic)
Makes copies of DNA
Holds cell together, Keeps organelles in place
Protects and supports cell
Not organelles, Make proteins
2 types of ribosomes
Free and bound
Make proteins that stay within the cell
Make proteins that will leave the cell
The endoplasmic reticulum is composed of small tubes called _________
Helps with the synthesis of lipids, phospholipids, and steroids, Helps break down carbohydrates (ex. Glycogen ((stored sugar)) to Glucose), Helps to detoxify blood (Liver cells = Lots of ____)
Smooth Endoplasmic Reticulum (SER)
Helps with protein synthesis (provides a H2O free environment for protein folding), Ribosomes are bound to the outside and deposit proteins inside as it is made by the ribosome
Rough Endoplasmic Reticulum
Modifies proteins by attaching sugars (called Glycoproteins)
(It’s like a gift wrapping to disguise the protein for export through the cell membrane), composed of flattened tubes called cisternae
Act like the “stomach” of the cell, Involved in digestion and recycling (autophagy), Full of digestive enzymes (lysozomes), Composed of phospholipid bilayer
Act as “closets” for storage of materials
Various types exist (food, contractile, central)
Vacuoles and Vesicles
The process of bringing something into the cell
Process of cell “eating”
The process of cell “drinking”
Involved in making energy by the performing the process of cellular respiration, Has its own DNA, Has cristae (folded inner membrane) that increases surface area for making energy, _________ matrix has ribosomes and is the site for the Kreb’s Cycle of Cellular Respiration, Evolutionarily significant
Site of photosynthesis in plants and algae, They are a type of plastid (any of a class of small organelles containing pigment or food.), Has its own DNA ribosomes and enzymes (ATP synthase)
Site of light reaction of photosynthesis (ATP from reaction will be used as energy for making sugar in Calvin Cycle)
Stack of thylakoids
Watery space between thylakoids and outer membrane (site of Calvin Cycle of Photosynthesis)
Proposed that prokaryotes came to live in a symbiotic relationship (the smaller living inside the larger), Eventually these prokaryotes evolved into eukaryotic cells over hundreds of thousands of years
Benefits of a smaller cell living inside a larger
Larger gains energy
Smaller gains protection
Helps support and protect the cell, Keeps inner organelles organized, Helps with motility, Composed of various sized protein fibers, Composed of microtubules
What is motility?
Large hollow tubes, Composed of tubulin protein, Main function is for support and movement, Help guide movement for organelles
Anchor during cell division, made of microtubules
“Tow ropes”, Used to move chromosomes during mitosis or meiosis, made of microtubules
Help with cell movement through wavelike movements
Help with cell movement, Fewer than cilia and longer in length, Undulating (whipping) movement
Smallest structures in the cytoskeleton, Solid rods, Composed of actin or myosin protein, Provide a “pulling force”, Abundant in muscle tissue
For protection and durability (holding up plant structure)
Primary cell wall composition
Middle lamella composition
Pectin sugar (“Super glue” between cell walls that hold them together)
Secondary cell wall composition
Outer protective “skeleton” of the cell plasma membrane in animal cells
Also functions in communication with other cells (use glycoproteins to communicate)
Composed mostly of glycoproteins and glycolipids
Help to hold cells together so they may work together
Some are tunnels for cell to cell communication
Composed of cells
Responds/adapts to environment
Grows and reproduces
Characteristics of a living thing
Said to be selectively permeable, Phospholipids make up the majority of it
Meaning of cell membrane being selectively permeable
Selects what materials enter or exit the cell through the membrane
Membrane also helps to regulate control of homeostasis (stable internal environment) by controlling entry and exit of certain molecules
These molecules are said to be amphipathic (have a hydrophobic and hydrophilic region)
These molecules created bi-layer and the structure is held intact by the presence of water inside and outside the cell
Remember proteins fold into 3D structures and that proteins are composed of amino acids that have water _______ and water ________ regions)
Two types of membrane proteins
Types of membrane protein, Run completely through the bi-layer from outside to the inside, These function in the transport of molecules and for stability (help maintain integrity of the structure)
Type of membrane protein, Located on 1 side of the membrane (do not extend into the bi-layer of the membrane), Act as sites for attachment of the cytoskeleton
Functions of membrane proteins?
Transport (Move food, water, etc across membrane), Act as enzymes (control metabolic processes), Cell to cell communication and recognition (so cells can work together in tissues), Intercellular junctions (for “stitching” together to make tissues), Attachment points to the cytoskeleton and extracellular matrix
This molecule helps keep the membrane of all cells flexible
Helps to keep the membrane of plant cells from freezing solid in very cold temperatures (like the Tundra)
Cell membrane characteristics as a moving puzzle because all pieces can move laterally (from side to side)
Fluid Mosaic Model
______ and ____ (both gases) diffuse across the wet phospholipid bilayer (example of diffusion)
CO2 and O2
_____ (charged particles) and water move through proteins (hence the name transport protein)
Operates upon an established  gradient, Materials flow from high  to low  until equilibrium is reached, This is how a majority of materials are transported into the cell (requires no energy)
Water always flows from hypotonic to hypertonic until isotonic (name of process)
Referring to water
Pure water is _________. (hypertonic, hypotonic, isotonic)
Water molecules ______ stop moving across the membrane even when in isotonic state
Condition when there is plenty of water in the plant cell (plant is rigid and stiff)
Condition when there is not enough water in the plant cell (limp and wilted)
When the cell membrane rips away from the cell wall killing the plant cell
Represented by the Greek symbol psi-Ψ
Water’s ability to perform work while passing through the cell membrane
Water moves from high potential (_______) to low potential (________)
The meaning of facilitate
Is a type of diffusion, The movement requires the help of a transport protein, Does not require energy to occur (Example: Calcium)
Requires energy, Moving material against the  gradient
(Examples: Proton pumps, Na+/Ka+ pumps of the nervous system)
Attaching phosphorus to an inactive ATP to make it active
Two types of large molecule transport
Two types of endocytosis (cell eating and drinking)
Phagocytosis and Pinocytosis
Main purpose of reproduction by cells
propagation (maintaining) of the lineage
the cell that divides into 2 daughter cells
The parent cell divides into 2 genetically identical __________ _______
The daughter cell are identical to each other and the previous __________ cell
The cells growing and being able to perform its adult functions
The cell cycle is necessary for normal _________ (as in the size of organs) and _________ (of existing structures)
growth and repair
The entire genetic material (DNA) for an organism or cell
Can genomes vary?
Yes they vary from species to species.
The genome length for humans is about ___ m or ____ ft per cell.
2m or 7ft
The two different states of DNA
chromosomes and chromatin
Chromatin can be moved around to find the gene segment of interest for __________ ____________.
Chromosomal content of somatic cells is ___ or ______.
2n or diploid
Half (in terms of chromosomal content) is referred to as _______ or __.
haploid or n
How many chromosomes do human cells have?
The proteins that help DNA coil up (condense) to form the chromosomes needed for division
means portion (ex. chromatid)
Half of a duplicated chromosome
The two halves of sister chromatid are held together at the _______ (means center unit)
The centromere is a group of _________.
This process refers to ordinary cell division (Parent cell and daughter cells are exactly alike genetically). Involves only one division after replication occurs in the synthesis phase)
Cells spend 90% of their existence in this phase
3 parts of interphase
G1, Synthesis, G2
First part of interphase. Primary or first growth. This is ordinary, everyday growth, activity, or repair of the cell. First checkpoint (called "point of no return") is the barrier to the rest of the cycle
Second part of interphase. The DNA replicates or is synthesized during this phase. In humans we go from 46 chromosomes "2n" to 92 chromosomes "4n"
Third part of interphase. Secondary or second growth. The cell and organelles mainly enlarge or replicate. Second checkpoint occurs after this part. Second checkpoint asks "do we have everything for 2 cells? If yes, the proceed to dividing, if no then make what is missing"
Means "nucleus division" (First divide the DNA; then secondly the cytoplasm.)
Four parts of mitosis
Prophase, Metaphase, Anaphase, Telophase (PMAT)
1 step in mitosis. Nucleus envelope is broken down and rearranged to make the spindle apparatus. The chromatin condenses to form X shaped chromosomes (2 chromatids). The centrioles move toward the poles (In animal cells only, plant cells use the cell wall)
Prophase ("pro" means first)
2nd step in mitosis. The replicated chromosomes line up on the metaphase plate (middle of cell). The spindle apparatus attaches to the kinetochore (a part of the centromere) and centrioles (the anchors). Third checkpoint occurs here. (Are all the chromosomes attached and lined up and ready to "divide/separate" or "segregate"?)
Metaphase ("meta" means middle)
3rd step in mitosis. Replicated chromosomes are pulled apart into sister chromatids and each chromatid moves toward opposite poles of the cell. The spindle apparatus is being broken down as the two sister chromatids are "walked" toward the poles by the motor protein using ATP.
Anaphase ("ana" means separate)
4th step in mitosis. The nuclear envelope is rebuilt by using broken down spindle apparatus pieces. The chromatids begin to de-condense back to their chromatin stage. A cleavage furrow (indent) begins to form using actin and myosin microfilaments
Telophase ("telo" means last)
The cytoplasm and cell organelles are separated to produce two daughter cells. This is the division of the cytoplasm.
Cytokinesis (cleavage means "split")
Occurs before G1. The cells are tired and take a brief break and rest.
G0 (Zero growth phase)
These structures are formed from the broken down cytoskeleton and nuclear envelope (recycled). The construction starts at the centrosome (where the centrioles are) and works toward the chromosomes. They attach to the replicated chromosomes. Motor protein "walks" the sister chromatids toward the opposite poles (ends) using ATP by phosphorylation. Non-kinectochore spindles are used to "push" the poles farther apart and help produce the cleavage furrow.
Plant cells do not have centrioles because they have ______ _______ to anchor to.
The new cell wall "______" develops, using small segments of cellulose, instead of a cleavage furrow.
This is the process of Reproduction/Replication in prokaryotes (bacteria). DNA replication (S phase) starts at the "origin" and works around the entire singular circular chromosome, this results in two identical chromosomes in the nucleoid region. This is followed by producing a cleavage furrow (cytokinesis) to produce 2 new cells that are referred to as clones. The cleavage furrow is produced using actin and myosin microfilaments.
How is Binary Fission related to mitosis in terms of evolution?
Binary Fission would have evolves into Mitosis as the DNA content increased dramatically and also used the endosymbiont hypothesis occurred to produce "organelles." The two major steps are the same: synthesis and division.
Regulation is crucial for normal _______ and _____________.
growth and development
Regulation ______ for each different type of cell.
molecules that regulate/control the cell cycle
Stopping points to make sure everything is correct before going on to the next phase
It is at the end of G1 (Called the Restriction point) "point of no return"
It is at the end of G2 (Do we have 2 sets of DNA and 2 sets of organelles?)
It is at the end of metaphase (Are all the replicated chromosomes in the middle of the cell and are they ALL attached to the spindle fibers?)
Cell division is a huge E consuming process, so rest is required for the cell.
G0 (resting state)
Abnormal cell growth
No __________ exist within cancerous cells, so there is no density-dependent inhibition.
Cancer starts with transformation of the DNA (________) in a cell
means Abnormal growth
Usually not deadly-easy to cure by removal of the tumor (It is encapsulated-like a tennis ball.) (This kind is non-invasive)