Semester 1 study guide

Science Study Guide

Metric Measurements

Mass=Gram=g

Volume=Liter=L

Distance=Meter=m

Temperature=Celcius=c

Characteristics of life

1.Cell Theory: All living things are made up of cell.

2.Universal Genetic Code: All organisms store complex information needed to function in DNA.

3.Homeostasis: All living things can maintain internal conditions.

4.Evolution: Population of living organisms change over time in response.

5.Growth and Development: All living things grow and develop.

6. Reproduce: All organisms produce either Sexual or Asexual.

7.Respond to their environment: Organisms detect and then respond to stimuli

8.Energy use and transfer: All organisms need energy and transmit energy   

Big ideas of biology

Evolution:The process of evolution drives life

Homeostasis:Biological system uses free energy and building blocks

Information:Living systems store and retrieve, transmit, and respond

Interdependence:Interact, and their interactions possess complex properties

Microscopes

Microscopes-devices that produce magnified images of structures that are small to see with the unaided eye.

Light microscope-magnifies images by focusing visible light rays; up to 1000x

Electron microscope- magnifies images by focusing beams of electrons, magnifies 100x more than light microscopes   

Steps of scientific method

1. question
2. collect info
3. hyposthesis
4. experiment
5. results
6. analysis

Nature of matter

Atom is the basic unit of matter

Proton- positive charge

Neutron- no charge

Nucleus- center of atom made of proton and neutron

Electron- negative charge, moves around the nucleus.

Periodic table-shows all elements known in a comprehensive fashion

Types of bonds:

Ionic bond- form when an atom gains or losses an electron

Covalent bond-electrons shared between atoms

Hydrogen bonds-not as strong a covalent or ionic bonds, but holds molecules together due to slight attraction of positive to negative charged regions

Why is water wet?

Polar- Unequal distribution of charge between

Water is very attractive

Cohesion-attraction between molecule of same substance

Adhesion-attraction between molecule of different substances

Capillary action- Cohesion+adhesion, causes H2O to rise up vs. force of gravity

Mixtures and solutions

Mixtures-material composed of +2 elements that are physically mixed together

Solutions- all components evenly distributed throughout

    Solute- substance that is dissolved

    Solvent- substance that the substrate dissolves

Suspension-mixture of H2O and an undissolvable material because pieces are so small that they do not settle out

Acids, Bases, and pH

pH is the measurement of H+ ions in a solution

Scale from 0 to 14

7=neutral, H+ ions=OH-

<7 is acidic, H+>OH-

>7 is basic, H+<OH-             

Acid- Tastes sour, corro-

sive to metals, become

less acidic when mixed

with bases, attracted to

bases.

Bases-Tastes bitter, feel

slippery, become less

basic when mixed with

acids, attracted to acids

Carbohydrates

The big 4 macro molecules:

1. Carbohydrates   
2. Lipids
3. Proteins
4. Nucleic acids

1. Carbohydrates:

Carbohydrates=sugars=saccharides

A. Structure: rings of CHO

B. Function: energy storage, and main source of energy. Broken down by mitochondria to make ATP. excess sugars= fat

2 types of carbohydrates

1. Monosaccharides:simple sugar, one ring, tastes sweet, example is glucose
2. Dissacharides: simple sugar, two rings, sweet, example is sucrose
3. Polysaccharides: 3 or more rings, tastes starchy or plain, also known as complex carbohydrate

A. starch is stored in plant, digestible, examples are bread, grains, and beans etc.

B. Cellulose, building blocks of plants, indigestible, examples are fruit and vegetables

The bad sugar:Fructose

naturally found in fruits. Unnaturally added as high fructose corn syrup in everything from bread to soft drinks. When consumed in fruit with lots of cellulose, the body can process it. By itself, it's a poison like alcohol. The body uses the lover to metabolize it.

Lipids

lipids are large molecules that include phospholipids, oil, fats, waxes and cholesterol

It is long chains of carbon and hydrogen called fatty acids.

Most are nonpolar

Many have 2 parts: hydrophilic(charged) head and hydrophobic(uncharged) fatty acid tail. Hydrophobic= water fearing, Hydrophilic= water loving

Example: Phospholipids

Functions:

1. energy storage, break bonds
2. make up cell membranes
3. used to make hormones
4. Fats and oils have 2 types of fatty acids

1. Saturated fats, straight chains of C and H can be bad for health in excess, solids at room temperature. Examples: Butter, lard, cheese etc.
2. Unsaturated fats, some carbon in chain are double bonded, better for health, liquids at room temperature, comes from plant products. Examples: canola oil, vegetable oil, and almonds etc.

Proteins are large molecules made of smaller molecules called amino acids chained together

How to make it:

eat protein-> body breaks body into amino acids-> acids recycled into new proteins

They support body (structural proteins), help cells (surface proteins), Speed up chemical reactions (enzymes), and let things through cell membrane (channel proteins)

1. Hemoglobin carries oxygen in the blood
2. Kerratin make up : nail, hair, fur
3. Muscle proteins make up muscle proteins
4. Collagen, most abundant protein in your body. Makes up skin, tendons, cartilage, bone, and more

Substrate- molecule the enzyme work on

Active site- where substrate attaches to enzymes

Product- What enzyme produces

Enzymes are the machine of the body. Make reactions faster, more product in less time, lowers activation energy.

Nucleic acids are large molecules composed of up to thousands of repeating nucleotides, they are made up of a 5-carbon sugar, a phosphate group and a nitrogenous base

Nucleotides bond together to make one strand or two strands,

Deoxyribonucleic acid (DNA) has two strands

Ribonucleic acid (RNA has single strand)

DNA serves as blueprint for making proteins

Source of information passed on from generation to generation

ATP

One phosphate molecule, adenosine triphosphate, is the primary energy transferring in the cell.

ATP consists of an organic molecule called adenosine attached to a string of three phosphate

Protein/Enzyme structure

Primary structure:individual amino acids chained together

Secondary structure: individual amino acid makes 2n hydrogen bonds with each other

Tertiary Structure: Stronger bonds between amino acids cause further foldings

Quaternary Structure: Multiple tertiary structures bond together to make larger protein

pH effects enzymes if it is too high or low and makes it become denatured and does not work as well.

Temperature, too hot or too cold, enzyme becomes deformed.

Denature: When an enzyme or protein losses its ability to do work

Completely denature: Breaks down primary structure irreversible

Membranes

Two layers of phospholipids, often with other macromolecules embedded, flexible. Function is a barrier, a container, and barrier.

1.Nuclear membrane holds in DNA in nucleus, allows RNA to leave through pores.

2.Lysosome holds enzymes for recycling proteins

3.Endoplasmic Reticulum holds proteins as they are finished off, hold lipids as they are made

4.Vesicles export molecules out or into the cell

5.Golgi Apparatus packages and secretion of finished proteins, lipids and hormones

6.Membranes in chloroplast and mitochondria, energy: carbohydrate creation and carbohydrate breakdown

7.Cell membrane holds all cell contents inside, protects from outside environment, controls passage of molecules inside.

All membranes are selectively (semi-) permeable which means some molecules can cross the membrane which others cannot

1. Passive transport is with no effort

1. Diffusion: movement of small molecules from high cell concentration to low through lipid bilayer, ex: water
2. Facilitated diffusion: proteins make it possible for larger molecules to pass through membrane, ex: glucose

2. Active transport is transportation with energy put in, energy is used to bring rare but highly needed molecules in the cell

Diffusion is high to low

Osmosis is the diffusion of water across a membrane, low to high concentration. More solute outside cell so solvent moves out of cell, cell shrinks because loss of water.

Tonicity- cell to gain or lose water

Isotonic- solution same as cell

Hypertonic- more than the cel

Hypotonic- less than the cell

Plasmolysis is when the cell membrane pulls from cell wall

Cells specialize in making proteins

Blueprint to build protein comes from DNA in the nucleus called gene

1. protein put together by ribosomes
2. passed to endoplasmic reticulum, they finish there
3. finished proteins, sent to apparatus via vesicles
4. golgi apparatus ships proteins

Heterotroph: any organism that gets energy from other organism (consumer)

Eukaryote: large cell with nucleus

Endosymbiotic theory: the theory that explains how big cells eat bacteria, become it. 1 million chloroplast and mitochondria can survive on their own.

Eukaryotic cells

1. Protists: heterotrophic, and autotrophic. Have all major organelles, moves using flagella, make vs. sick. examples euglena, amoeba, paramecium, and plasmodium
2. Plant cells: have organelles, cell wall, cell, vacuole, chloroplast. examples: all plants such as trees
3. Animal cells: part of multicellular organism, but also unicellular. Examples any of your cells

Endocytosis- process of taking in material

Phagocytosis- cell eating, exterior of cytoplasm surrounds a part and packages it with a food vacuole

Pinocytosis- take in liquid, tiny pockets form along cell membrane, fills with liquid, pinches off in the cell

Exocytosis- release of material, membrane of vacuole surrounds material, fuses with cell membrane, force out of cell

Photosynthesis:Plants produce glucose and oxygen using sunlight and carbon dioxide. 6CO2+6H2O+light->C6H12O6+6O2

Photosynthesis                                  Cellular respiration

3 only reasons for the cell cycle

1. Reproduction, only way for single cell organisms to reproduce, ensures offspring to have same DNA, Binary fission is when bacteria reproduces, often reproduce experimentally.
2. Growth and development, baby to adult, individual cells grow so that it is large enough to divide into two cells.
3. Cell/tissue repair, multicellular organisms, grow more, cells to replace damaged or killed cells, scrapes cuts heal because of surviving skin cells reproduce to replace damaged ones, sleep is when cells that are damaged are replaced.

problems

cancer is caused by mistakes in the cell, either occurring out of control or chromosomes not separating equally. Some cells don't reproduce at all, neutrons (brain cells) stop dividing after your early twenties. Red blood cells constantly reproduce, needed to carry oxygen in blood. Many diseases and syndromes caused by unequal of chromosomes (DNA), example down syndrome.

The Cell Cycle

1. interphase: DNA is copied
2. Mitosis: DNA and organelles are split up
3. Cytokinesis: Cell divides into two cells

1. Interphase
1. G1: cell grows
2. S: DNA copies itself
3. G2: CEll prepares for division
2. Mitosis

1. Prophase

1. DNA becomes visible

Chromatin becomes Chromosomes

       Chromatin= DNA that is stringy, Chromosome= DNA that is ropelike

       b. nuclear membrane disappears

B. Metaphase

a.chromosome lines up st equator

C. Anaphase

a.spindle fibers pull chromosomes apart

D. Telophase

a.nuclear membranes form

b.spindle fibers disappear

3.   Cytokinesis

Cell splits into two genetically identical cells

1. Rest of organelles are divided
2. Cell membranes pinch apart.

Types of reproduction

Asexual, only 1 parents, offsprings are genetically identical

Sexual, two parents, each parent contributes half of offsprings DNA through sperm or egg, each offspring is genetically different.

Asexual

binary fission: bacteria divides (mitosis)

budding: piece of organism breaks off

regeneration: regrow body parts

vegetative propagation: parent produces parts that become individual

benefits of asexual reproduction, easy, takes short amount of time, don't need a mate, can make a lot of offsprings

costs, no genetic variation=not resistant to change, more likely to become extinct due to change of environment

Sexual

broadcast spawning: Sea urchin releasing sperm/egg into water

paired spawning: Salmon lay eggs then male deposits sperm

spores: fern create spores that land on the ground, grow and create structures that will reproduce

seeds: pollen delivers sperm to female part of flowers, seed is offspring

copulation: mammals, reptiles, amphibians

benefits, creates genetic variation, can allow parents to raise young to ensure survival, creates competition for mates, ensuring, best pass on their genes

costs, requires lots of energy, exposes you to parasites, creates genetic combinations that are bad, creates competition- not all get to reproduce

meiosis is process of making gametes in testes or ovaries

1. produces genetically unique cells
2. results in haploid cells
3. takes place only at certain times in a organism's life cycle
4. involved in sexual reproduction

Crossing over occurs during prophase1, when chromosomes pair up and then they swap chunks of DNA

Haploid vs Diploid

haploid: have one copy of every chromosome and include 22 autosomes and 1 sex chromosome

diploid: cells have two copies of every chromosome, asexual reproduction: always produces diploid cells

Meiosis creates gametes with half the number of chromosomes from 2n to n, gametes carry chromosomes, sex is fusing of gametes to make cell with all chromosomes from n to 2n

each chromosome has many genes, all genes determine an organism's traits, trait: characteristics, Gene: a piece of DNA that gives an organism's its traits.

Genotype: the alleles that and organism has

Phenotype: the physical trait that results due to an organism alleles

Homozygous: having two of the same allele

Heterozygous: having two different alleles

Genes are sections of DNA that determine physical trait, they are found on chromosomes

Alleles: are different variations of genes, they come in pairs

Mendel's law of segregation:

The gene pairs for a trait separate when gametes are formed

Mendel's law of independent assortment

Gene pairs separate independently, or randomly from each other during meiosis

Autosomal inheritance: organisms inherits or gets the gene responsible for a trait from all the other 22 chromosomes

x-linked inheritance: organism inherits or gets the gene responsible for a trait from the x chromosome

Autosomal dominance

1. bipolar disorder
2. widows peak
3. tongue curling

Autosomal recessive

1. albinism
2. cystic fibrosis
3. sickle cell anemia

Sex linked dominance

1. coffin lowry syndrome: physical and mental handicap

X-linked recessive

1. color blindness
2. hemophilia

Incomplete dominance: neither allele is completely dominant nor recessive, results is heterozygous phenotype is different than the two homozygous phenotype

Codominance: both alleles will both be completely expressed

Gene linkage: because chromosome have many genes, the closer they are together, the none likely they are to be inherited together

Epistasis: one gene alters the phenotype expression of another gene

Multifactorial disorder: is where the environment effects genetics

Polygenic: when two or more genes determine the phenotype of an individual

DNA= deoxyribonucleic acid

Deoxy= without oxygen

Ribo= has a ribose sugar in it

Nucleic= in nucleus

Acid= pH of less than 7

Structure:

1.Double helix: two strands twisted around each other

2.made of 3 nucleotides, each made up of 3 parts

nitrogen base, a phosphate group, a sugar

phosphate and a sugar make up the sides of the ladder and bases are the steps

3.DNA is antiparallel, each nucleotide covalently bonds with another. The -OH group on the 3 carbon of one nucleotide with the phosphate in the 5 carbon on the next

Comes in two types:

1. double rings called, purines, example: adenine and guanine
2. single rings called, pyrimidines, example: thymine and cytosine

All cells have DNA, all multicellular organisms have identical DNA in all of their cells, DNA codes for traits of an organism, before a cell divides DNA must be copied/replicated in order for both cells to be identical.

Semi conservative DNA replication:

Creates: 2 identical strands of DNA from 1 strand, two strands end up with half of the original strand

Step 1: unzipping, enzyme unzips DNA by breaking hydrogen bonds that hold nitrogen bases together(G to C,A to T)

Step 2: matching, DNA polymerase ( another enzyme) add matching (bases) to each strand

Result: two identical, two DNA molecules from that are identical to the original DNA molecule

DNA -> RNA -> Protein -> Organism

Structural differences between DNA and RNA

1. single standed
2. has ribose- not deoxyribose
3. contains uracil instead of thymine

DNA= master copy

RNA= temporary copy of DNA

Function of DNA

1. serves as temporary copy of a gene
2. delivers the copy to the ribosome
3. ribosomes uses this copy to make protein

Transcription ( in the muscles)

the process where RNA polymerase reads and copies the DNA code (gene) for a protein as mRNA copy

3 steps of transcription

1. DNA unzips
2. RNA polymeraze matches spare nucleotides to make and RN strand
3. Messenger RNA or mRNA is produced and leaves nucleus for cytoplasm

Translation ( in the cytoplasm)

1. mRNA arrives at the ribosome
2. Ribosomes reads mRNA 3 bases at a time and translates DNA language (nucleotides: A,G,C,U) into protein language
3. Each three base sequence of A,G,C,U as a codon. Each codon codes for one amino acid
4. AUG is known as start codon because it tells the ribosome to start translating. There are also codons

The result of translation

1. long chains of amino acid
2. chain of amino acids twist, fold, combine with other chains and becomes a protein

Mutations: change in DNA

Mutagen: anything that causes mutation

Point mutations.

Change in 2 or 2 base pairs of DNA

Very small, common

Harmful- protein changes a lot

little harmful- protein does not change

2 types

1. substitution- 1 nucleotide is substituted for another
2. frameshift- an extra base pair is put in the code, deletion, base pair is left out

Other mutation

inversion- DNA breaks, then bonds reverse order

translation- part of chromosome, break of joins another

Change in DNA=Change in protein

Gene expression: gene used to make a gene product or phenotype

Gene regulation: cells used to increase or decrease expression of a gene

Cells don't look the same but have the same DNA, this is because they express only some genes

Cells do not want to waste energy

• promoter: located on DNA where DNA polymerase attaches
• Operon: genes that control the expression of a gene
• Operator: allows or denies RNA polymerase from attaching and reading the gene

Eukaryotic regulation:

RNA processing: after transcription sections of the gene are removed

Exons- sequences that are expressed

Introns- sequences that are cut out

Histones- proteins that allow DNA to coil

Nucleosomes: DNA wrapped 2x around a histone

Gene whose promoters are wrapped up in nucleosomes are not expressed

Different enzymes break histones free or bind them to control gene expression. This is passed on

• why not every gene is expressed