Bio exam 1

Why cell biology is important

it helps us understand how cells function and interact, leading to advancements in medicine, genetics, and biotechnology. It provides insights into diseases, drug development, and organ transplantation.

Scientific method

A way of learning about the world through observation and experimentation

observe: watching or measuring

data: record observation

experiment: a well controlled test

Why science matters in todays society

drives innovation, solves problems, and improves our lives. It helps us understand the world around us, Science provides evidence-based information, guiding policy decisions and shaping public understanding.

control group

a group separated from the rest of the experiment

independent variable

variable controlled by the scientist

dependent variable

variable measured by the researcher

boring water stimulates…

evaporation in primordial ocean

A mixture of water vapor, gasses, and electrical discharge stimulates…

lightening

Abstract

a brief overview

Introduction

background

Materials and methods

how experiment was preformed

results

description of data, analyses, figures, and tables

Discussion

interpret results, refine hypotheses

References

research and other information cited in the paper

Nature of atoms

Matter has mass and occupies space

all matter is made up of …

atomic structure

made up of protons, neutrons, and electrons

Electrons

Negatively charged particles located in orbitals

cation

more positively charged particles then negative

anion

more negatively charged particles than positive

neutrons

atoms that have the same number of protons and electrons

Redox

when electrons are transferred from one atom to another during a chemical reaction

oxidation

loss of an electron

Reduction

gain of an electron

hydrogen bonds

formed when slightly negative oxygen on one water molecule Is attracted to the slightly hydrogen molecule of another water molecule

Cohesion

polarity of water allows water molecules to be attracted to one another

Water is a good solvent

water dissolves polar molecules and ions

Water organizes non polar molecules

water causes hydrophobic(water fearing) molecules to aggregate or assume specific shapes

Properties of water

water is a good solvent

water organizes non ploar molecules

water can form ions

ph

measure of the hydrogen ion concentration in a solution

acids and bases

• Release H+ ions, lower pH, taste sour, turn blue litmus paper red.

  Release OH- ions, raise pH, taste bitter, turn red litmus paper blue.

• pH Scale: Measures acidity/basicity, ranges from 0 (acidic) to 14 (basic), 7 is neutral.

• Neutralization: Reaction between acid and base, forms water and a salt.

buffers

substance that resists ph changes by releasing or absorbing hydrogen ions

Carbonic acid and bicarbonate

key buffer in human blood

hydrocarbons

Organic compounds made up of only hydrogen and carbon atoms.

polymer

built by linking monomers

monomers

small, similar chemical subunits

dehydration synthesis

formation of large molecules by removing water

monomers are joined to polymers

hydrolisis

breakdown of large molecules by adding water

polymers are broken down to monomers

carbohydrates

Molecules with a 1:2:1 ration of carbon hydrogen and oxygen

good energy storage molecules

Monosaccharide

Simpliest carbohydrate

6 sugars play important roles

Structural isomer

compound with the same formula but different atom arrangement

stereo isomer

each of 2 or more compounds differing only in spatial arrangement of their atoms

Disaccharide

2 monosaccharides linked together by dehydration synthesis

used for sugar transport or energy storage

polysaccharides

long chains of monosaccharides linked together by dehydration synthesis

Energy storage form polysaccharides

plants use starch

animals use glycogen

cellulose

plants use this for structural support

chitin

arthropods and fungi use this for structural support

lipids

non polar hydrophobic organic molecule that is insoluble in water but dissolves readily in nonploar solvents

ex: fats, oils, steroids, phospholipids

polar molecule

A molecule with a partial positive charge on one end and a partial negative charge on the other end, due to an uneven distribution of electrons.

non polar molecule

A molecule with an equal distribution of charge, resulting in no positive or negative poles.

triglycerides

composed of 1 glycerol and 3 fatty acids

saturated fats

no double bonds between carbon atoms

unsaturated fats

1 or more double bonds

trans fat

produced industrally

phospholipids

a molecules with 2 fatty acids and a modified phosphate group attached to a glycerol background

Micelles

lipid molecules orient with polar(hydrophilic) head toward water andnonpolar (hydrophobic) tails away fromwater

Phospholipid bilayer

more complicated structure where two layers form

hydrophilic

head points outward

hydrophobic

tails point inward towards each other

Proteins

composed of 1 or more long, unbranched chain

each chain is a polypeptide

Amino acid

monomer

types of amino acids

histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine

peptide bond

formed through dehydration synthesis

Primary structure

sequence of amino acids

secondary structure

interaction of groups in the peptide backbone

tertiary structure

final folded shape of a globular protein

Quaternary structure

arrangement of individual chains in a protein with 2 or more polypeptide chains

motifs

common elements of secondary structures seen in many polypeptides

useful in determining function of unknown proteins

domains

Functional units within a larger structure

perform different parts of the protein’s function

chaperones

Once thought newly made proteins folded spontaneously

help protein fold correctly

Nucleic acids

polymer

nucleotide

basic building block of RNA and DNA (Nucleic Acids)

nucleotide structure

DNA

Encodes information for amino acidsequence of proteins

RNA

similar to DNA except– Contains ribose instead of deoxyribose– Contains uracil instead of thymine

Prokaryotic cell

Simplest organisms

Lack a membrane-bound nucleus

DNA is present in the nucleoid

Cell wall outside of plasma membrane

Do contain ribosomes (not membrane-bound organelles)

Domains are bacteria and Archaea

cell theory

All organisms are composed of cells

2. Cells are the smallest living things

3. Cells arise only from pre-existing cells

All cells today represent a continuous line of descent from the first living cells

What kills bacteria

Antibiotics

Bacteria cell wall

Protect cell, maintain shape, prevent uptake/ loss of water

composed of peptidoglycan

Gram postiive

Darker

Gram negative

lighter

Eukaryotic cells

Possess a membrane-bound nucleus

Hallmark is compartmentalization achieved through use of membrane-bound organelles and endomembrane system

Possess a cytoskeleton for support and to maintain cellular structure

Organelles

Small structures within cells that perform specific functions. Examples include the nucleus, mitochondria, and endoplasmic reticulum.

Nucleus

Where DNA is stored

Nucleous

region where ribosomal RNA synthesis takes place

Chromatin

DNA + Protein

Ribosomes

Cell’s protein synthesis machinery

Found in all cell types in all 3 domains

mRNA

Transcript

rRNA

protein complex

tRNA

carry amino acids

rRNA

Structural

Mitochondria

Found in all types of eukaryotic cells

Bound by membranes

Outer membrane

Intermembrane space

Inner membrane has cristae

Matrix

On the surface of the inner membrane, and also embedded within it, are proteins that carry out oxidative metabolism

Have their own DNA

chloroplasts

Organelles present in cells of plants andsome other eukaryotes

Contain chlorophyll for photosynthesis

Surrounded by 2 membranes

Thylakoids are membranous sacs within the inner membrane

– Grana are stacks of thylakoids

Have their own DNA

Endosymbiosisbiosis

the theory that organelles were created by prokaryotic cells being engulfed and becoming apart of another cell