ccm-bio 1-exam 2

Chargaff's rules state

- A=T and G=C - percentages of nucleotide bases

Cell theory states

- All living things are made up of cells - cells are the basic (smallest) units of life - new cells are produced from pre existing cells

Proofread and repair

- DNA polymerase 3 reads pair once bonded - nuclease can cut out damaged segment and DNA poly 1 will correct the gap

Microtubules (cytoskeleton)

- biggest of the 3 - hollow tubes (spindal fibers) - made of tubluin

Extracellular components

- cell wall (plants) - extra cellular matrix (animal) -plasmodesmoda (tight) (gap) (desmosomes)

intermediate filaments (cytoskeleton)

- many proteins coiled into cables - maintenance of cell shape - anchor of nucleus and other organelles

Integral Proteins

- penetrate the hydrophobic interior - some are transmembrane proteins

Microtubules in cell division

- result from the centromeres - attach to the kinetochore to pull sister chromatids apart

Microfilaments (cytoskeleton)

- two intertwined stands of actin - muscle contraction - changes in cell shape - division of cell (animal)

leading strand

5' to 3' direction.

binary fission

A form of asexual reproduction in a bacteria call where a chromosome replicates and moves to different sides of the cell allowing for replication

Cytoskeleton

A network of fibers that provides support and stability

Nucleus

A part of the cell containing DNA and RNA and responsible for growth and reproduction

plasma membrane

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

Co-transporter

A type of carrier protein that binds two molecules at the same time

proton pump

An electrogenic pump that works largely with H+ ions.

Helicase

An enzyme that untwists the double helix of DNA at the replication forks.

Lysosomes

An organelle containing digestive enzymes - phagocytosis = food digestion - autophagy = digestion of damaged cell materials

kinetochores

Anchor on the Sister Chromatid that attaches to the fiber that pulls the sister chromatids apart.

Centromere

Area where the chromatids of a chromosome are attached

function of membrane proteins

Attachment to cytoskeleton and extracellular matrix. Maintains cell shape and stabilizes cytoskeleton. ... Intercellular joining. Proteins on adjacent cells hook together, briefly, for cell interaction/sharing. ... Signal transduction. ... Enzymatic activity. ... Cell-cell recognition. ... Transport.

cyclin-dependent kinase

CDK (enzyme) binding with cyclin (two proteins) creates = MPF (maturation-promoting factor)

Pinocytosis

Cell drinking

elctrochemical gradient

Chemical force: Ion Concentration Gradient Electrical force: Membrane Potential - charge difference - (if negative charge on the outside of the cell they might not want to come in if they are the same charge)

Phagocytosis (cell eating)

Cytoplasmic extensions surround object and bring it into cell.

DNA structure

DNA consists of two antiparallel chains of nucleotides (A,T,G,C) twisted into a double helix

Meselson and Stahl

Determined that DNA replication is semiconservative. - 5'-P to 3'-OH'

Hersey and Chase

Discovered that DNA is the genetic material, NOT protein

active transport

Energy-requiring process that moves material across a cell membrane against a concentration difference

Prokaryote vs. Eukaryote cells

Eukaryote cells-Membrane bound organelles, nucleus Prokaryote cells-Simple cells, no nucleus;

sister chromatids

Identical copies of a chromosome; full sets of these are created during the S phase of interphase.

Glycolipids

Membrane carbohydrates that are covalently bonded to lipids. - Short branched chains of 15 or fewer monosaccharides

Glycoproteins

Membrane carbohydrates that are covalently bonded to proteins. - Short branched chains of 15 or fewer monosaccharides

transport proteins: channel proteins

are passageways through the plasma membrane, allowing specific ions or molecules (water) to enter or exit the cell; may be gated or nongated

single strand binding proteins

bind to the unpaired DNA strands, keeping them from re-pairing

Telomerase

catalyzes the lengthening of telomeres in sex cells

density dependent inhibition

cells form a single layer and divide to fill gap and then stop

M checkpoint

checks for chromosomes attached to the microtubule

Prophase

chromosomes condense, centrosomes start to move, nuclear envelop starts to dissolve (lipid bilayer comes apart)

Metaphase

chromosomes will line up in the middle with microtubules connected (chromosome with its copy (sister chromatids)), centrosomes are at opposite ends

Peroxisomes

contain enzymes that create peroxide by stripping H atoms from substrates and adding them to oxygen

central vacuole

contains inorganic ions & enlarges due to water absorption

Topoisomerase

corrects "overwinding" ahead of replication forks by breaking, swiveling, and rejoining DNA strands

Griffith's experiment

dead pathogenic bacteria can transform-non material

passive transport

diffusion Across the biological membrane without using energy

ficilitated diffusion

diffusion for large molecules with the help of protiens - no energy

associated proteins

function to maintain the structure of chromosomes and to help control gene activity

Rough ER function

glycoslation of proteins & regulation of protein traffic

Why do cells divide?

growth, repair, reproduction

Ligase

joins Okazaki fragments of lagging to leading

peripheral proteins

loosely bound appendages to membrane

G1 checkpoint

makes sure the conditions are favorable and the cell is healthy enough to enter the next stage

endosymbiont theory

mitochondria and chloroplasts were once prokaryotic cells not always organelles and a eukaryotic cell ate it and they formed a symbiotic relationship

Gogli Apparatus

modification, storage, and shipment of materials to other destinations

Mitochondria

organelle that is the site of ATP (energy) production

Mitosis

part of eukaryotic cell division during which the cell nucleus divides

Endocytosis

process by which a cell takes material into the cell by infolding of the cell membrane

transport proteins: carrier proteins

proteins that help carry substances across the membrane or allow molecules to pass through a channel

contractile vacuole

pumps excess water out of the cell to maintain ion/molecule concentration

Exocytosis

release of substances out a cell by the fusion of a vesicle with the membrane.

DNA polymerase

removes RNA nucleotides of primer from 5' end and replaces them with nucleotides added to 3' end of an adjacent fragment

scanning electron microscope

scans the outside (makes a 3D pic)

transmission electron microscope

shows the inside through the slice

cytoplasmic face

side of plasma membrane that faces inward

Extracellular face

side of plasma membrane that faces outward

Anaphase

sister chromatids come apart

Ribosomes

site of protein synthesis

G1 phase

stage of interphase in which cell grows and performs its normal functions

fluid mosaic model

structural model of the fluid phospholipid bilayer and the mosaic of proteins

why are cells small

surface area to volume ratio

lysis of the cell

swelling and possible tearing from a gain in water

Primase

synthesizes an RNA primer at 5' end of leading strand and at 5' end of each Okazaki fragment of lagging strand

Osmosis

the diffusion of Water across a selectively permeable membrane

Diffusion

the movement of particles into open space down a Concentration Gradient

S phase

the portion of interphase during which DNA is replicated.

electrogenic pump

transport protein generates voltage across a membrane

Telophase

two nuclei form, de-condensing chromosomes, forming of cleavage furrow

DNA polymerase III

using parental DNA as a template synthesize DNA strand by adding nucleotides to the 3' end of a preexisting DNA or RNA primer

Plasmolysis

walled cells in which the cytoplasm shrivels and the plasma membrane pulls away from the cell wall; occurs when the cell loses water

Crenate

when a cell shrinks due to water loss

Isotonic

when the concentration of two solutions is the same

Genome

all of the DNA located in a cell

endomembrane system

-plasma membrane -nuclear envelope -endoplasmic reticulum - golgi apparatus -lysosomes - vesicles and vacuoles

lagging strand

3' to 5' direction

Telomeres

Repeated DNA sequences at the ends of eukaryotic chromosomes. - buffer zone for erosion - prevent cell death from staggered ends

Chloroplast

Site of photosynthesis

Okazaki fragments

Small fragments of DNA produced on the lagging strand during DNA replication,

hypertonic solution

Solute concentration is greater than that inside the cell; cell loses water

hypotonic solution

Solute concentration is less than that inside the cell; cell gains water

somatic cells vs gametes

Somatic cells: (body cells) have 46 chromosomes in humans Gametes: (reproductive cells) have 23 chromosomes in humans

Vacuoles

Stores food, water, wastes, and other materials

Smooth ER function

Synthesis of lipids Detoxification of poisons

G2 checkpoint

The cell checks to make sure the DNA is copied correctly

anchorage dependence

The requirement that to divide, a cell must be attached to a solid surface.

G2 phase

The second growth phase of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs.

Prometaphase

The second stage of mitosis, during which the nuclear envelope fragments and the spindle microtubules attach to the kinetochores of the sister chromatids.

receptor-mediated endocytosis

The uptake of specific molecules based on a cell's receptor proteins

sodium-potassium pump

a carrier protein that uses ATP to actively transport sodium ions out of a cell and potassium ions into the cell

turgid cell

a plant cell that has absorbed water and has cytoplasm that is pressing outwards on the cell wall