Biology Semester 1

Molecule

Molecule

A group of atoms bonded together

cell

smallest unit of life

Community

all of the populations of organisms within a given area

Ecosystem

the interaction of a community and the physical enviorment

organ system

group of organs that work together to perform a specific function

Population

A group of individuals that belong to the same species and live in the same area

Biosphere

all the regions of earth that hold organisms

Organ

interaction of 2 or more tissues to perform a common task

Tissue

organized groups of cells that interact for a specific task

Atom

the fundamental unit of matter

Multicellular organism

individual composed of different types of cells

Hypothesis

testable explanation of a situation

control group

does not have the "thing" that you are testing

Testable Question

A question that can be answered by conducting an experiment

prediction

if-then statement

experimental group

has the "thing" that you are testing

independent variable

I set up before the experiment starts

dependent variable

being measured during the experiment

Control Variables (constants)

are kept the same between the experimental and control group

Carbohydrates

starches and sugars that provide short term energy and cell structure

Lipids

fatty acids and glycerol, tryglyceride, phospolipids, steroids provide long term energy

Proteins

amino acids that are linked by peptide bonds provide structure, energy storage, contrcative(muscle movement), transport

nucleaic acid

nucleotides(sugar, phospate group, nitrogen base) DNA and RNA

Condensation

covalent bonding of two molecules to form a larger molecule. water forms as a product

hydrolosysis

reverse of condensation, cleavage teactions split larger molecules into smaller ones. water is split

prokaryotic cell

A type of cell lacking a membrane-enclosed nucleus and membrane-enclosed organelles;Bacteria

Eukaryotic cells

Larger, complex, with nucleus, membrane bound organelles, DNA tightly wrapped around histone proteins in chromosomes, cellulose in plant cell walls. Plant and Animal Cells

Nucleus

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

Nucleolus

Found inside the nucleus and produces ribosomes

smoothe ER

Makes lipids

nuclear envelope

Double membrane perforated with pores that control the flow of materials in and out of the nucleus.

Rough ER

That portion of the endoplasmic reticulum studded with ribosomes. folds and modification of proteins

Lysosomes

cell organelle filled with enzymes needed to break down certain materials in the cell

golgi

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

Ribosomes

Makes proteins

Mitochondria

makes ATP

cell membrane

A cell structure that controls which substances can enter or leave the cell.

cell wall

gives support to plant cells

Cytoskeleton

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

Vesicles

small membrane sacs that specialize in moving products into, out of, and within a cell

Centrioles

Cell organelle that aids in cell division in animal cells only

centeral vacuole

Particularly large vacuole that stores water, only in plant cells

Chloroplast

An organelle found in plant and algae cells where photosynthesis occurs

Oraganelle

A membrane-bound structure inside a cell that performs a specialized function

Cytoplasm

A jellylike fluid inside the cell in which the organelles are suspended

Vacuole

A sac inside a cell that acts as a storage area

endomembrane system

A network of membranes inside and around a eukaryotic cell, related either through direct physical contact or by the transfer of membranous vesicles.

active transporters

proteins that move molecules through membrane by using energy

transport proteins

allow materials to pass through membrane

intergral proteins

general name for proteins that are physically embedded

recognition proteins

provide a "fingerprint" for the cell, so it can be recognized by other cells

perphial proteins

general name of proteins found on the surface of the membrane

Recepetor Proteins

bind substances on the exterior that trigger changes inside cell

passive transporters

allows materials to pass through membrane without using energy

adhesion proteins

helps cells stick together

Diffusion

diffusion across a membrane

active transport

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

Osomosis

water moves from an area of high water concentration to an area of a low water concentration

passive transport

the movement of substances across a cell membrane without the use of energy by the cell

facilitated diffusion

Movement of specific molecules across cell membranes through protein channels

Endocytosis

A process in which a cell engulfs extracellular material through an inward folding of its plasma membrane.

Exocytosis

Process by which a cell releases large amounts of material

cell cycle

series of events that cells go through as they grow and divide

Gap 1 (G1)

cells grow, carry out normal functions, and replicate their organelles

Synthesis Phase

DNA is replicated

Gap 2 (G2)

Additional growth happens and the cell prepares for mitosis

Interphase

Cell grows, performs its normal functions, and prepares for division; consists of G1, S, and G2 phases

Prophase

Chromosomes become visable, nuclear envelop dissolves, spindle forms

Metaphase

Chromosomes line up in the middle of the cell

Anaphase

Phase of mitosis in which the chromosomes separate and move to opposite ends of the cell

Telophase

phase of mitosis in which the distinct individual chromosomes begin to spread out into a tangle of chromatin

Cytokinesis

division of the cytoplasm

Mitosis

part of eukaryotic cell division during which the cell nucleus divides

daughter cells

the two new cells that result from mitosis and cytokinesis

Chromosomes

a long strand of DNA organized around proteins

sister chromatids

Identical to each other, duplicated amd condensed, has centramere to hold them together

unduplicated chromosome

A un-copied portion of DNA that is made of many genes in a condensed form.

Chromatin

Substance found in eukaryotic chromosomes that consists of DNA tightly coiled around histones

Nucleosome

repeating subunit of chromatin fibers, consisting of DNA coiled around histones

Gene

A segment of DNA on a chromosome that codes for a specific trait

Karyotype

A picture of all the chromosomes in a cell arranged in pairs

why do we need more cells?

growth,repair,replace,asexual reproduction

DNA

deoxyribonucleic acid

DNA nucleotide

Deoxyribose Sugar, Bases GCAT, and Phosphate Group

RNA nucleotides

Ribose sugar, phosphate group, bases AUCG

Purines

Bases with a double-ring structure. Adenine and Guanine

Pyrimidines

Bases with a single-ring structure (cytosine, thymine, uracil)

complementary base pairing

Hydrogen bonding between particular pyrimidines and purines. Adenine & Thymine. Cytosine & Guanine.

5' end and 3' end

5' end - has a 5' carbon attached to a phosphate 3' end - has a 3' carbon attached to a hydroxyl group

Chargraff's Rule

amount of adenines = amount of thymines; amount of guanines = amount of cytosines

Rosalind Franklin

Used X-ray diffraction to discover the double-helical structure of DNA.

James Watson and Francis Crick

1953. Built first accepted DNA model explaining specific structure and properties of DNA.

DNA replication

the process of making a copy of DNA

DNA helicase

unzips the DNA strand

Topoisomerase

prevents overwinding and tangling

single strand binding proteins

hold strands apart, making sure that they don't connect again

RNA primase

An enzyme that creates a short RNA primer for initiation of DNA replication.

DNA polymerase III

adds DNA nucleotides to the open 3' side of RNA nucleotides and then keeps adding DNA nucleotides to the open 3' end side on the newly made DNA

leading strand

DNA nucleotides are being added in the same direction towards the helicase

lagging strand

DNA nucleotides are being added in the opposite direction as the helicase