Ch.2 pt.2

Rough Endoplasmic Reticulum function

-produces more membrane for the cell -assists in protein folding of proteins that will be exported/secreted by the cell (ex: protein hormones)

The relaxed euchromatin state of DNA is best utilized for which function?

Access for gene expression

Smooth Endoplasmic Reticulum

An endomembrane system where lipids are synthesized, calcium levels are regulated, and toxic substances are broken down.

Lysosomes

An organelle containing digestive enzymes

Mitochondria

An organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur.

Centriole

Cell organelle that aids in cell division in animal cells only

Centrioles

Cell organelle that aids in cell division in animal cells only

inclusions

Chemical substances such as stored nutrients or cell products

Which of the following structures are typically associated with ribosomes?

Cytosol Mitochondria Rough endoplasmic reticulum

Central Dogma of Genetics

DNA -> RNA -> Protein

Nucleolus

Dense region of the nucleus where ribosomes are made

Where do peroxisomes come from?

ER

cisternae

Flattened, membrane-bound compartments that make up the Golgi apparatus.

The structure in which ribosomal RNAs are synthesized in the nucleus is termed which of the following?

Nucleolus

Where are you most likely to find carbohydrates associated with the plasma membrane

Outside surface

intermediate filaments

Threadlike proteins in the cell's cytoskeleton that are roughly twice as thick as microfilaments

transmembrane proteins

Transmembrane proteins are integral proteins that do not extend all the way through the membrane.

Endoplasmic Reticulum

a network of interconnected membranes of tubules and cisternae with a large surface area

cell membrane

a phospholipid layer that covers a cell's surface and acts as a barrier between the inside of a cell and the cell's environment

what do nucleosomes control?

access to DNA

what type of enzymes are in lysosomes

acid hydrolases

What do ribosomes do?

forms a complex between mRNA and tRNA molecules

Where are ribosomes found?

free-floating in the cytosol, or bound to the rough ER, inside the mitochondria, or the nuclear envelope

de novo gene expression

generation of brand new proteins from scratch from DNA--> RNA --> Proteins

nuclear pores

holes in the nuclear envelope that allow materials to pass in and out of the nucleus

Heterochromatin

inactive DNA

Effect of temperature effect of fatty acid saturation effect of of cholesterol

increase temp=increase fluidity increase unsaturaturated FA= inc. fluidity inc. cholesterol=decreased fluidity

Which type of membrane protein is most likely used to transport molecules across the plasma membrane?

integral

inner membrane

linked by lamina that help maintain nuclear shape and serve as a scaffold to organic DNA

lipid rafts

localized region of membrane lipids, often characterized by elevated levels of cholesterol and glycosphingolipids, that sequester proteins involved in cell signaling; also called lipid microdomain

Ribosomes

made up of ribosomal RNA and proteins that orchestrate the protein translation process

Vacuole

membrane-bound vesicle for temporary storage of materials such as food, enzymes, and wastes

mRNA

messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome

What cellular organelle is most affected by CO poisoning?

mitochondria

where is dna also found

mitochondria

fluid mosaic model

model that describes the arrangement and movement of the molecules that make up a cell membrane

Golgi apparatus function

modifies, packages, stores, and transports lipids made by Smooth ER

Intron

non-protein coding regions of the genome

what are the primary structures of the nucleus

nuclear envelope nucleolus chromatin

Nucleus

organelle composed of a double membrane that acts as the storehouse for most of a cell's DNA

what does the mitochondria have

own DNA, RNA and ribosomes can reproduce themselves

Peroxisomes function

oxidation of fatty acids, ethanol, or other compounds detoxification neutralizing free radicals

Which of the following accurately represents the three basic parts of the cell?

plasma membrane, cytoplasm, nucleus

bound ribosomes

produce proteins that will generally be used in membranes or packaged to be sent to other locations in the body

free ribosomes

produce proteins that'll function in the cytosol

Glycocalyx functions

protection, immunity to infection, defense against cancer, transplant compatibility, cell adhesion, fertilization, embryonic development

Exons

protein coding regions of the genome

What is the end-product of metabolic activity according to the central dogma of genetics?

proteins

what happens in the cisternae

proteins are modified, tagged, and stored for delivery

terminator region

region on gene that marks the end of transcription

Cholesterol

regulating membrane fluidity, substrate for steroid hormones

Chromatin

relaxed form of DNA in the nucleus of a cell

Flippase

requires ATP to transport lipids from one leaflet to another

rRNA

ribosomal RNA; type of RNA that makes up part of the ribosome, helps to recognize the codons in an RNA message

biological membranes

selectively permeable membranes that help maintain homeostasis in the cell

Autolysis

self-destruction of cells; decomposition of all tissues by enzymes of their own formation without microbial assistance

peripheral

signal transduction, enzymic activity, cell adhesion process

Peroxisomes

small membranous sacs containing oxidase and catalase

lumen

space within a tubular part or organ, such as the space within a blood vessel

Cytosol

the aqueous component of the cytoplasm of a cell, within which various organelles and particles are suspended.

genes

the biochemical units of heredity that make up the chromosomes; a segment of DNA capable of synthesizing a protein

aerobic cellular respiration

the process by which cells use oxygen to obtain usable energy from an energy source

Golgi apparatus

traffic director for cellular proteins

what is the delivery side of the Golgi apparatus called

trans face

What kind of molecule induces the expression of specific genes?

transcription factor

tRNA

transfer RNA; type of RNA that carries amino acids to the ribosome

oxidace

use O2 to detoxify harmful substances converting free radicals into H2O2 (hydrogen peroxide)

Cytosol

viscous, semitransparent fluid substance of cytoplasm in which other elements are suspended

Euchromatin

where active RNA production is occurring

Rough Endoplasmic Reticulum

System of internal membranes within the cytoplasm. Membranes are rough due to the presence of ribosomes. functions in transport of substances such as proteins within the cytoplasm

Subunits of ribosomes

1. large: three sites for binding and RNA 2. small: binds mRNA

What does chromatin consist of?

30% DNA, 60% histone, 10% RNA

phospholipid bilayer

A double layer of phospholipids that makes up plasma and organelle membranes.

nuclear envelope

A double membrane that surrounds the nucleus in the cell

Cytoplasm

A jellylike fluid inside the cell in which the organelles are suspended found outside the nucleus

Cytoskeleton

A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement

Autophagy

A process in which lysosomes decompose damaged organelles to reuse their organic monomers

Myosin

A protein present in muscle fibers that aids in contraction and makes up the majority of muscle fiber

plasma membrane

A selectively-permeable phospholipid bilayer forming the boundary of the cells

Centrosome

A structure in animal cells containing centrioles from which the spindle fibers develop.

Golgi apparatus

A system of membranes that modifies and packages proteins for export by the cell

Organelle

A tiny cell structure that carries out a specific function within the cell

Where do lysosomes come from?

Golgi apparatus

what keeps pH low in membranes

H+ pumps

A fully processed mRNA molecule should contain all of the following except what?

Intron

Microfilaments

Long, thin fibers that function in the movement and support of the cell

Which of the following statements correctly describes the Fluid Mosaic Model? Select all that apply.

Membrane proteins can move laterally. Phospholipids can rotate.

transcription factors

Proteins that bind promoters and instruct RNA polymerase as to whether the gene should be transcribed or not

intergral proteins

Proteins that go all the way through the membrane

With which structure would you expect a cell to produce steroids?

Smooth endoplasmic reticulum

Microtubules

Spiral strands of protein molecules that form a tubelike structure

Glycocalyx

The external surface of a plasma membrane that is important for cell-to-cell communication

peripheral proteins

The proteins of a membrane that are not embedded in the lipid bilayer; they are appendages loosely bound to the surface of the membrane.

What do proteins do?

catalysis, defense, movement, signaling, structure, transport (work of the cell)

alternative splicing

certain exons are retained and others are spliced out

what is the receiving side of the Golgi apparatus called

cis face

promoter region

contains the start signal for the beginning of instructions

outer membrane

continuous with the RER

Catalase

convert H2O2 into H2O

Saturation

degree of hydrogen content bound to carbon in fatty acid tails