biology final review

DNA

DNA structure and replication nuclecic acids hold our DNA it contains genes which are sections of DNA that work as instructions to make proteins .

Two types :DNA and RNA

a nucleotide( part of nucleic acid ) had three parts sugar,phosphate, and nitrogen base (adenine,guanine,cytosine,thymine(DNA only),uracil (RNA only)

DNA structure double helix

DNA is antiparallel

DNA is in the nucleic acid

Purpose is to replicate DNA for healing and growth

In a prokaryotic cell it is in the chloroplast

in a eukaryotic cell it is in the nucleus

it gets copied during a process called replication these happens during S phase

Enzymes and their functions in DNA replication

helicase -unzips DNA

primase-Tells DNA to build the “starter”

DNA polymerase- builds and checks for errors and corrects them

Ligase-”glues” everything

DNA polymerase synthesizes the new DNA strand

DNA polymerase travels from 5’ to 3’

3 differences between the leading strands and lagging strand

1. lagging strands (okazaki fragments)have more fragments

2. leading strands only need polymerase

3. lagging strand needs both polymerase and primase

DNA replication creates new strands it is semi-conservative because it keeps and old stand and a new stand

DNA contains:

these nitrogen bases A,T,C,G

sugar used deoxyribose

its shape is a single strand

Basics of heredity

chromosomes tightly coiled strands

different organisms have different numbers of chromosomes humans have 46 in total 23 pairs from mom and 23 from dad

gene a section of DNA that has instructions to code protein

one chromosome can contain thousands of genes linked together

so genens are pieces of DNA chromosomes are long strands of DNA all bunched up

DNA replication

when a cell is divided it has to copy DNA first called DNA replication this happens in the nucleus during S phase

1.DNA unzips to two strands

protein synthesis

The process of reading the instructions in DNA to make a polypeptide

A polypeptide is a chain of amino acids folded into proteins

Central dogma of genetics

DNA is located in the nucleus proteins are made in ribosomes

protein synthesis happens in 2 steps c called transcription and translation

DNA———-> (transcription)RNA——->(translation) Protein

Three essential types of RNA

mRNA ( messenger)

copies instructions in DNA and carries these on the ribosomes in the cytoplasm

tRNA ( transfer)

binds and carries specific amino acids to the ribosomes.

rRNA (ribosomal)

along with proteins make up the ribosome.

-help catalyze the form of peptide bonds

transcription

purpose:to produce a strand of mRNA and DNA

location:nucleus

translation

mRNA makes polypeptide(protein)

Purpose:read/follow instructions carried on the mRNA to make a polypeptide

location: ribosomes

codon= a set of 3 nucleotides on mRNA

3 codons equal 1 amino acid

anticodon-three nucleotides located at the end od a transfer RNA molecule

a purpose of an anticodon is to ensure the correct amino acid is added to the growing polypeptide

translation can occur and the cytoplasm and the rough ER

meiosis

our body has 2 types of cells

somatic cells body cells

meiosis

haploid its sex cells

for females it happens in the womb

for males it happens throughout life

ovaries and testes

makes babies

PMAT twice

4 unique haploid

sexual reproduction

23 sex cells

mitosis

diploid somatic cells

throughout life

where body

for growth and repair

PMAt once

2 identical diploid

asexual reproduction

photosynthesis

equation 6CO2+ 6H20—> C6H1206+6O2

enothermic

recantants carbon dioxide and water

products glucose and oxygen

step one light dependent reaction

occurs in the grana

makes oxygen uses water powered by sunlight

sunlight is absorbed by chlorophyll a pigment in the membrane of the thylakoid

step two

light independent powered by the ATP/NADPH from light dependent

light independent occurs in the stoma uses carbon dioxide makes glucose stroma is a part of chloroplast

cellular respiration

equation C6H12O6—->6CO2+6H2O+ATP

exothermic

reactions glucose and oxygen

products carbon dioxide and water

starts with glycolysis, which occurs in the cytoplasm

glycolysis creates energy-carrying molecules like ATP, NADH

glycolysis splits the glucose into oxygen

with oxygen goes to aerobic respiration starts with krebs cycle which occurs in the matrix

krebs cycle breaks pyruvate into ATP and ends with ETC occurs in the inner membrane

ETC creates water an ATP using ATP krebs cycle carries energy molecules like NADH,FADH2,ATP

without oxygen goes to anaerobic respiration also called fermentation in animals is latic acid in yeast alcohol both create atp