Biology- Basis of Life Flashcards
What kind of nutrients did heterotrophs require?
Nutrients from outside sources or preformed materials….they cannot synthesize nutrients.
First living organisms were called…
Heterotrophs
What organic molecules were made in the Miller experiment? How?
Urea, hydrogen cyanide, acetic acid and lactic acid. They were made from the combination of heat and UV radiation with methane, hydrogen, ammonia and water.
What are coacervate droplets? And what was learned from them?
Cluster of protein/colloidal molecules that is surrounded by water.
They absorb from the environment and could selectively metabolize.
Those that reproduced had nucleic acid polymers.
What changed heterotrophs to autotrophs?
The development of biochemical pathways helped them be able to use a variety of materials.
What event made heterotrophs and autotrophs develop aerobic respiration?
Autotrophs began making carbs from the water and carbon dioxide in the air and as a result O2 was released into the atmosphere.
Example of autotrophic anaerobe:
Chemo synthetic bacteria
Example of autotrophic aerobe:
Green plants and photo plankton
Example of heterotrophic anaerobe:
Yeast
Example of heterotrophic aerobes:
Humans, earthworms and amoebas
Define protoplasm
All living things
Element unit
Atom
Compound unit
Molecule
Chemical makeup of carbs
C:H:O
1:2:1
Function of carbs
Store energy (glucose and glycogen in animals and starch in plants) Provide structure
4 examples of monosaccharides
Glucose, fructose, galactose, mannose
2 examples of disaccharides:
Maltose and sucrose
What are polysaccharides? Examples?
Insoluble in water; chain of monosaccharides
Cellulose (plant structure), glycogen and starch
How are disaccharides made?
Dehydration synthesis (loss of water)
Components of a lipid and how lipids are made
3 dehydration synthesis reactions (cannot be polymers) 3 FAs (hydrophobic and acidic) an glycerol
Function of lipids
Store energy in animals and protect/insulate
What are phospholipids?
2 FAs and glycerol Phosphate group N-containing alcohol Lecithin (cell membranes) Cephalin (brain, nerves and nerve tissues)
What are waxes?
Esters of FAs and monohydroxylic alcohols….protective coatings
What are steroids made of? Example?
3 cyclohexane rings and 1 cyclopentane ring
Cholesterol, testosterone and estrogen, and corticosteroids
What are carotenoids? Examples?
FA carbon chains with double bonds and cyclohexane rings on each end.
Pigments (carotene and xanthophyll)
What are porphyrins? Example?
4 pyrrole rings fused together. Metal complex as well.
Ex: heme with Fe complex or chlorophyll with Mg complex
What are proteins also called?
Polypeptides and polymers
Dehydration synthesis that combines amino acids by peptide bonds
Primary vs Secondary protein structures
Primary: AA sequence
Secondary: coil or fold (helix or B-pleated)
Structure of simple proteins:
Only made of AAs
Structure of albumins and globulins:
Globular in form…..they are functional and act as carriers or enzymes.
Structure of scleroproteins:
Fibrous and structural…..collagen
Structure of conjugated proteins:
Simple protein portion and nonprotein portion
Structure of lipoproteins:
Bound to lipids
Structure of mucoproteins:
Bound to carbs
Structure of chromoproteins:
Bound to a pigmented protein (carotenoids)
Structure of metalloproteins:
Complexes around a metal ion
Structure of nucleoproteins:
Bound to nucleic acids (DNA or RNA)….in dab the protein is combined with histone or protamine
Function of hormones:
Chemical messengers that are secreted in circulation.
Examples: insulin and ACTH
Function of enzymes. How do they work?
Catalysts that increase the speed of a rxn by decreasing the activation energy. DONT change G of rxn.
Function of structural proteins:
Physical support
Extracellular: collagen in tendons and bones
Intracellular: cell membrane proteins
Function of transport proteins:
Carry materials.
Example: hemoglobin carries O2 or cytochromes carry electrons in cell respiration
Function of antibodies:
Bind to antigens and fight them to protect the body.
Name of the molecule an enzyme acts on:
Substrate
Area on enzyme where the substrate binds is called:
The active site
Which theory of enzyme specificity is more widely accepted?
Induced fit hypothesis (the active site conforms shape to fit the substrate) NOT lock and key.
Are enzyme reactions reversible?
Yes and the same enzyme can be used to reverse the reaction.
As temperature increase, the rate of enzyme actions……
Increase until an optimum temperature is reached when the enzyme is deactivated.
Maximal pH of human body enzymes:
7.2(the ph of body fluids)
What environment does pepsin work best in?
Acidic conditions like in the stomach….pH = 2
What environment do pancreatic enzymes work best in?
Basic intestinal conditions…pH =8.5.
When substrate and enzyme concentrations are low….
Slow rxn because active sites are empty
Increased substrate concentration will….
Increase reaction rate until all active sites are full (this is the maximum velocity of the reaction)
Lactase hydrolyzes lactose into
Glucose and galactose
Proteases do what?
Degrade proteins in amino acids
Function of lipases
Break lipids into FAs and glycerol
Where does protein synthesis take place?
In ribosomes (dehydration synthesis with amino acids)
What are coenzymes?
Nonprotein molecules that enzymes need to be active. Can be cofactors like Fe or Zn. Cannot be synthesized by body and are obtained as vitamin derivatives.
Define prosthetic groups:
Cofactors that bind to the enzyme with covalent bonds
Nucleic acids are made up of
Nucleotides
5 components of the cell theory:
Cells are basic functional unit of life All living things are composed of cells Cells only come from pre-existing cells Cells carry genetic info as DNA. (Passed from parent to daughter cell in cell division) Energy flow occurs within cells.
What does the fluid mosaic model say?
Cell membrane consists of phospholipid bilateral with proteins throughout. Lipids and proteins can move freely.
Function of nucleus:
Controls activities and cell division.
Surrounded by nuclear membrane.
Contains DNA which is complexed by histones = chromosomes.
What happens in the nucleolus?
Ribosomal RNA synthesis.
Function of ribosomes:
Protein production.
Made by nucleolus.
Free ribosomes= cytoplAsm
Bound ribosomes=outer membrane of endoplasmic reticulum
Function of endoplasmic reticulum:
Transport materials (especially waste)
Function if Golgi apparatus:
Receives vesicles from smooth ER, modifies them and repackages them into vesicles and uses exocytosis to get them to cell surface
Function of mitochondria:
Aerobic respiration…supplies energy.
Has phospholipid bilayer
Function of cytoplasm:
Metabolic activity
Cyclosis: movement of cytoplasm that provides transport
Function of vacuole:
Membrane bound sacs that transport and store materials in the cell. Vacuoles are bigger than vesicles and are in plants.
Function of centrioles:
Microtubule involved in spindle organization during division. Not bound to membrane. Only in animal cells (2 of them are perpendicular) in the centrosome.
Function of lysosomes:
Membrane bound vesicles that have hydrolytic enzymes for digestion. Break down material ingested by the cell. Autolysis is a cell killing itself by rupturing the lysosomes membrane.
function of cytoskeleton:
Composed of microtubules and micro filaments and gives cell mechanical support while maintaining it’s shape.
Cells like sperm that need a lot of energy will have a lot of….
Mitochondria
What is simple diffusion? Active or passive?
Movement down concentration gradient. Passive.
Osmosis.(passive or active?)
Passive. Water goes from low solute concentration to high solute concentration.
What is facilitated diffusion?
Down concentration gradine through special channels or carrier proteins. Does not require energy.
What is active transport?
Against concentration gradient with transport proteins….requires energy.
Brownian movement:
Intracellular Circulation. Spreading movement of suspended particles throughout cytoplasm via kinetic energy that is made from collisions.
What is Cyclosis or Streaming?
Circular motion of cytoplasm around the cell transport molecules.
What does the ER do in Intracellular circulation?
Provides channels throughout cytoplasm and provides continuous passage from plasma membrane to nuclear membrane.
Two forms of extracellular circulation:
Diffusion and Circulatory System.
