Honors Bio

Nucleus

Control center of the cell. Contains DNA.

Ribosomes

site of protein synthesis

Rough ER (endoplasmic reticulum)

A network of interconnected membranous sacs in a eukaryotic cell's cytoplasm; dotted with ribosomes that make membrane proteins and secretory proteins.

Smooth ER

That portion of the endoplasmic reticulum that is free of ribosomes.

Golgi

The Golgi apparatus consists of stacks of membrane-enclosed spaces that process, sort, and deliver proteins. It's membranes have enzymes that make additional changes to proteins. It also packages proteins. The packaged proteins are stored within the apparatus or transported to other organelles or outside the cell.

Cell Membrane

It is the boundary of the cell system that separates it from its surroundings. It is semipermeable, meaning it only lets certain things in and out of the cell.

cell wall

A rigid layer outside the plant cell membrane that gives protection, support, and shape to the cell.

Centrioles

cylinder-shaped organelles made of short microtubules arranged in a circle. Move to the poles, form spindle fibers, and pull chromosomes to each side of the cell.

Spindle Fibers

Microtubules that grow from the centrioles. They attach to DNA and help it divide between the two cells.

Mitochondria

The powerhouse of the cell; parts: matrix, inner membrane, inter membrane space, and the outer membrane.

Chloroplast

Plant organelle in which photosynthesis occurs. Has stacks of thylakoids in which light dependent reactions occur. Light independent reactions occur outside thylakoids.

Vacuole

A fluid-filled sac used for the storage of materials needed by the cell.

cell membrane function

Controls the movement of substances into and out of the cell

Stages of the cell cycle

interphase (G1, Synthesis, G2), Mitosis (prophase, metaphase, anaphase, telophase), cytokinesis

G1 (Gap 1)

Cell grows, carries out normal functions, and replicated organelles

Synthesis

DNA is replicated

G2

additional growth occurs

Interphase

Cell grows, performs its normal functions, and prepares for division; consists of G1, S, and G2 phases. DNA is loosely organized during this stage

Prophase

Chromosomes condense, nuclear envelope breaks down, centrioles begin moving to opposite poles, and spindle fibers form.

Metaphase

Spindle fibers attach to the centromere of each chromosome. They align the chromosomes along the middle of the cell

Anaphase

Sister chromatids are pulled to opposite sides of the cell.

Telephase

Two nuclei form chromosomes begin to uncoil.

Mitosis purpose

1: grow and develop 2: repair 3: replace

Cytokinesis

Animal: cell membrane pinched off and desperate cells are complete. Plant cells: a cell plate forms

Cytoplasm

fluid portion of the cell outside the nucleus, fills space, contains mostly water, which helps maintain structure and provide a medium in which chemical reactions can occur

Endoasmic reticulum (smooth and rough)

Interconnected network of thin, folded membranes. Numerous processes such as the production of proteins occur on the surface and inside this organelle.

Prokaryotic vs. Eukaryotic Cells

Eukaryotic cells have nucleus and membrane bound organelles. Prokaryotic cells (BACTERIA) are unorganized and don't have a nucleus

Cell Cycle checkpoints

mechanisms that monitor the preparedness of a cell to advance through the various cell cycle stages. They ensure certain conditions are met before cell moves past the stage.

Why does DNA coil

To fit a lot of DNA in a small space

Why is it misleading to call interphase the resting phase

Many important things happen during interphase

Chromosomes

One long continuous strand of DNA that consists of many genes.

replicated chromosome

A chromosome that has been copied; consists of two identical chromatids, each containing one double-helical DNA molecule

Chromatid

one half of a duplicated chromosome

sister chromatids

Replicated forms of a chromosome joined together by the centromere and eventually separated during mitosis.

Centromere

Area where the chromatids of a chromosome are attached. Centromeres are the middles

cell plate

A double membrane across the midline of a dividing plant cell, between which the new cell wall forms during cytokinesis.

What is the cell membrane made of?

phospholipid bilayer and proteins

Endocytosis

Letting things into the cell (study the diagrams of each type)

Phagocytosis (endocytosis)

The process by which a cell engulfs large particles or whole cells, either as a defense mechanism or as a means to obtain food (immune cells do it to engulf bacteria)

Pinocytosis (endocytosis)

The process by which a cell takes in liquid from the surrounding environment

receptor-mediated endocytosis

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

Exocytosis

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

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration. Moves molecules across the cell membrane

passive transport

No energy required; transport of small and medium materials across the membrane (Osmosis, Diffusion, and Facilitated Diffusion)

facilitated diffusion

Movement of specific molecules across cell membranes through transport protein

active transport

Energy(ATP)-requiring process that moves material (like Na+ and K+) across the cell membrane against the concentration gradient; example: moving Na+ and K+ against the concentration gradient in muscle cells and neurons

DNA stands for

deoxyribonucleic acid

DNA function

stores genetic information that controls protein synthesis

Gregor Mendel

The father of genetics - Experimented with pea plants

How similar is everyone genetically

99%

DNA fingerprinting

analysis of sections of DNA in order to identify individuals

Electrophoresis

A process where DNA fragments are separated according to size using electrical charges

Rosalind Franklin (study her in depth; she's defined gonna be on the test)

Took the first picture of DNA using X-ray crystallography

James Watson and Francis Crick

Used RF's work without giving her credit and created model of DNA

Photo 51

The most visible picture of DNA taking using x-Ray crystallography that gave Watson the information he needed to build his model.

DNA structure

DNA consists of two long chains of nucleotides (the monomer that makes up each side of DNA) stacked on top of each other and twisted into a double helix and joined by hydrogen bonds between the complementary bases adenine and thymine or cytosine and guanine.

Nucleotide

A nucleotide (sugar, base, phosphate) is 5 carbon sugars, one phosphate group, and 1 nitrogenous base. The nitrogenous base is connected only to the sugar, not to the phosphate. The sugar, also known as deoxyribose sugar, and phosphate alternate to make up the sides of DNA.

Purines

Bases with a double-ring structure (there bigger than pyrimidines). (Adenine and Guanine); PURe AGony

Pyrimidines

Bases with single ring structure (the smaller ones). Cytosine and Thymine, CuT the PY

# of rings in each "step" and # of bonds in each base pair

DNA allows for the width of 3 total rings along each step of the ladder (purines have 2 rings, pyrimidines have one). Between cytosine and guanine, there are 3 hydrogen bonds. Between adenine and thymine, there are two hydrogen bonds.

Chargaff's Rule

[A]=[T] and [G]=[C], they pair up across from one another forming two strands also called base pairing. This rule was important in determining the structure of DNA.

What determines your genes

The order of bases

Anti-parallel (will be on test)

It means that the two sides of DNA run in opposite directions. The nucleotides on one side of the DNA stack on top of each other, but the nucleotides on the other side of DNA stack on top of each other in the opposite direction.

3' and 5'

Apostrophe = prime; Direction of the sides of DNA. When DNA is replicated, the sides have to be replicated from 5' to 3'.

DNA replication purpose

To produce two sets of DNA for the two daughter cells

When does DNA replication occur?

synthesis phase (S phase) of interphase

DNA replication steps

unwinding, base pairing, joining

semi-conservative replication

Method of DNA replication in which parental strands separate (unzip), act as templates, and produce 2 molecules of DNA, each with one parental DNA strand and one new DNA strand

Unwinding

Helicase enzyme unwinds original DNA by breaking apart hydrogen bonds between bases. SSBs keep the DNA open and RNA primase adds the RNA primer.

SSBs (single stranded binding proteins)

proteins bind and stabilize the sides of DNA, keeping it from base pairing with itself or the other strand

RNA Primase and RNA primer

RNA Primase adds a short piece of RNA, called an RNA primer, to each strand of DNA. RNA primer is a short segment of RNA that acts as a red flag that tells the DNA polymerase where to start.

Base Pairing

The enzyme polymerase adds on the matching nucleotides for the new strand of DNA that forms. Because each strand has to be built from 5' to 3', the two strands have to be built in opposite directions.

Leading and lagging strands

leading is the strand that is added continuously in the 5'-->3' direction by DNA polymerase. lagging strand is made in 5'-->3' direction but discontinuous in okazaki fragments that require multiple RNA primers.

Okazaki fragments

Small fragments of DNA produced on the lagging strand during DNA replication, joined later by DNA ligase to form a complete strand.

Joining

when the DNA polymerase comes to an RNA primer on the DNA, it removes the primer and fills in the place with DNA nucleotidesOnce the RNA primer has been replaced, DNA ligase links the two sections.

replication bubbles

Because DNA replication does not happen from one end to another (it actually happens at multiple places at the same time), "replication bubbles" are created in the DNA.

parent strand and daughter strand

Parent strand: original strand of DNA from the original DNA (strand means side)Daughter strand: the new strand of DNA

results of mitosis

The two daughter cells have the same number of chromosomes and genetic material as the parent cell (if you want to repair, replace, or grow/develop, you want identical cells to the ones you start with)

Kram's B-day

Nov 24

DNA replication terms to know

Semi-conservative replication, parent strand, Template, Helicase, SSB (single stranded binding proteins), RNA primase, RNA primer,DNA polymerase, Leading strand, Lagging Strand,Okazaki Fragments, DNA ligase, Replication bubbles, Daughter Strand

mistakes in replication

DNA polymerase proofreads, however mistakes can happen. The mistakes cause mutationsPositive effects: the mutations can be positive and allow for evolution and adaptionNegative effects: cancer or mutations that hurt more than help