unit 1 Flashcards
unicellular:
organisms made of only one cell
multicellular
organisms made of many cells
organelles:
ultra-structures within cells which have a particular function
nucleus:
controls cell activities
cell membrane:
controls what enters and exits the cell
cytoplasm:
site of chemical reactions
ribosomes:
site of protein production
mitochondria
site of aerobic respiration
cell wall:
provide structure and support to the cell
PLANT = made of cellulose
FUNGAL AND BACTERIAL = made of different materials
vacuole:
contains cell sap and maintains turgar of cell
chloroplasts:
site of photosynthesis
plasmids:
extra circular piece of DNA used in genetic engineering
organelles found in animal cell:
mitochondria
nucleus
cel membrane
cytoplasm
ribosomes
organelles found in plant cell
nucleus
mitochondria
chloroplast
vacuole
cell membrane
cell wall
ribosomes
cytoplasm
organelles found in fungal cell:
nucleus
mitochondria
cell wall
cell membrane
cytoplasm
ribosomes
organelles found in bacterial cell:
lathe circular DNA molecule
plasmids
cytoplasm
cell membrane
cell wall
capsid
where does fermentation in yeast cells occur?
cytoplasm
examples of membrane bound organelles
nucleus
chloroplast
mitochondria
what are the cell membrane comprise of?
phospholipids and proteins
what does the cell membrane comprise of?
phospholipids and proteins
the phospholipids are arranged…
…in 2 layers to form a lipid bilayer
what is the cell membrane commonly described as?
fluid mosaic structure
what is embedded in the cell membrane?
proteins
the cell membrane is selectively permeable. what does this mean?
some small molecules such as oxygen and carbon dioxide pass directly through the phospholipid bilayer while other larger molecules are transported across the cell membrane by proteins.
what is diffusion?
the movement of molecules down a concentration gradient. (high to low)
what is a concentration gradient?
the difference in concentration of a substance between 2 areas.
passive transport:
requires no energy
why is diffusion important?
allows them to gain useful substances (to obtain energy and grow) and get rid of waste products
what is osmosis?
the movement of water molecules from a high to a low concentration gradient through a selectively permeable membrane.
cell shrinks/plasmolysed:
water concentration inside the cell is higher than outside so water moves out by osmosis.
cell stays the same:
water concentration outside the cell is the same as inside the cell so there is no net movement of water.
cell bursts/turgid:
water concentration outside the cell is higher than inside so water moves in by osmosis.
active transport:
the movement of molecules from an area of low concentration to an area of high concentration.
it is the movement of molecules and ions against a concentration gradient.
- requires energy
what is DNA?
a double stranded helix which is the information carrying molecule found in all living organisms.
where is DNA stored
nucleus
what are chromosomes
2 strands which coil to form thread like structures
genes:
section of DNA that’s codes for a protein
chromosomes are divided into…
packets of information called genes
DNA has 2 backbones..
held together by complementary base pairs
bases and their pairing in DNA:
ADENINE only pairs with THYMINE
CYTOSINE only pairs with GUANINE
how is a protein produced?
a molecule called mRNA copies the code from the nucleus and carries it to a ribosome where the protein is assembled from amino acids.
3 bases on the molecule of mRNA codes for one specific amino acid.
the base sequence determines amino acid sequence in the protein
what is a protein
a large molecule made up of amino acids
functions of proteins:
- structural (offer support to cell)
- hormones ( chemical messengers)
- receptors (signals transmitted across membrane)
- enzymes (speed up cellular reactions)
- antibodies (protect body from disease)
enzymes:
fixation as biological catalysts and are made by all living cells. they speed up cellular reactions and are unchanged in the process.
definition of substrate and products:
substrate - substance the enzyme acts upon
products - substance the enzyme makes
active site:
the area on the enzyme where the substrate attaches to (complementary)
enzyme-substrate complex:
the substrate and enzyme binded together
degradation and synthesis:
degradation - break down of molecules
synthesis - build up of molecules
optimum conditions:
the rate of enzyme activity is at its highest and most active
denatured:
due to high temps, enzymes have a change in their shape
stages of genetic engineering:
- human gene of interest identified
- human gene of interest cut from chromosome using enzymes
- plasmids from bacterial cell
- plasmid cut open using enzymes
- human gene sealed into plasmid using enzymes
- modified plasmid placed into bacterial cell (now known as genetically modified organism)
- bacterial cell is allowed to grow and replicate
what is genetic engineering
genetic information is transferred from one organism into another
what is respiration?
respiration is a chemical process that releases the stored energy from glucose through a series of enzyme-controlled reactions
what is respiration?
respiration is a chemical process that releases the stored energy from glucose through a series of enzyme-controlled reactions
word equation for aerobic respiration
glucose + oxygen —> carbon dioxide + water + ATP (lots)
what does aerobic respiration require?
oxygen
name the 2 stages of aerobic respiration
- glycolysis
- breakdown of pyruvate
GLYCOLYSIS:
during glycolysis, glucose is broken down in the cytoplasm of the cell. this produces 2 ATP and 2 molecules of pyruvate
BREAKDOWN OF PYRUVATE:
in the cytoplasm of the cell, pyruvate combines with glucose. this produces 2 ATP, carbon dioxide and water
what does ATP provide and what can it be broken down into?
ATP provides energy for cellular processes and can be broken down into ADP + Pi
how many ATP is produced in aerobic respiration?
first stage = 2 ATP
second stage = lots of ATP
how many ATP is produced during fermentation/anaerobic respiration?
1st stage = 2 ATP produced
2nd stage = NO ATP produced
word equation for fermentation in animals:
GLUCOSE —> LACTIC ACID + ENERGY
word equation for fermentation in plants and microorganisms:
GLUCOSE + CARBON DIOXIDE + ETHANOL + ENERGY
