Second partial Flashcards
What does the nucleus do?
Stores the genetic information of the cell
What do lysosomes do?
Break down macromolecules using digestive enzymes
What is the function of the mitochondrion?
Converts chemical fuel into packets of chemical energy (ATP) that can power the cell
What does the ribosome do?
Works with mRNA to synthesize proteins
What is the Smooth ER?
The site of lypid synthesis
What is the plant cell wall?
The strong, protective structure made from cellulose fibrils
What does the central vacuole do?
Regulates cytoplasm composition, creates internal pressure, and stores cell compounds
What does the chloroplast do?
Makes food by converting light energy into chemical energy
What does the Golgi Apparatus do?
Modifies and packages proteins
Which organelle serves as a protein manufacturing facility?
Rough ER
Which organelle provides structural support and provides tracks for moving organelles?
Cytoskeleton
What are centrioles in animal cells made out of?
Microtubes
Some eukaryotic cells have a ———- or a short —– that move.
Flagellum or short cilia
In facilitated diffusion, molecules use a ————- to move across the plasma membrane
transport protein
What is the fluid mosaic made out of?
Lipids
What are some of the functions of a membrane?
Isolate cell contents, regulate exchanges, create attachments, regulate chemical reactions
What is a solute?
The substance that disolves
What is a solution?
Where solute and solvent meet
What is the gradient?
The flow of solute
What is a hypotonic solution?
Where solutes are less
What is an isotonic solution?
Where there is the same quantity of a solute and a solvent
What is a hypertonic solution?
There is more solute than solvent
What is the main characteristic of passive transport?
No energy is required
What are the three types of passive transport?
Simple diffusion, osmosis & facilitated diffusion
Simple diffusion is mainly used for…?
Gases
Osmosis is used for…?
Water
Facilitated diffusion is used for…?
Specific molecules
What is the main characteristic of active transport?
It requires energy
Active transport is very selective in…?
What goes in & out
What is the formula for photosynthesis?
6 CO2 + 6 H2O —-light energy—> C6H12O6 + 6 O2
What is the function of photosynthesis?
To convert solar energy into chemical energy of a carbohydrate
What do plants produce?
Oxygen & glucose
What are autotrophs?
Species that make their own food
What are heterotrophs?
Species that require food from other producers
The first step of photosynthesis, the LIGHT REACTION, occurs where?
In the tylakoids
What happens during the light reaction process?
Light energy is converted into chemical energy
The second step of photosynthesis, the CALVIN CYCLE, occurs where?
In the stroma
Chlorophyll’s pigments reflect which color?
Green
Which colors are absorbed by chlorophylls?
Violet, blue, red & orange
What is the starting molecule in the light reactions?
H2O
Which molecules are produced during the light reactions?
O2, ATP & NADPH
Which are the starting molecules in the Calvin Cycle?
ATP, NADPH & CO2
Which molecules are produced in the Calvin Cycle?
ADP, NADP+ & Phosphate
Plants have a stomata, what does this do?
It opens & closes depending on the temperature. If it is hot, it won’t let water evaporate & vise-versa
What is the first step of cellular respiration?
Glycolysis
Where does glycolysis happen?
In the cytoplasm
What happens during the glycolysis?
Glucose is broken down into NADH, Pyruvic Acid & ATP
What is the second step of cellular respiration?
Acetulation
Where does acetulation occur?
In the mitochondria
What happens during the acetulation?
The pyruvates are broken down and carbon dioxide is released
What is the third step of cellular respiration?
The Krebs Cycle
Where does the Citric Acid / Krebs Cycle occur?
In the mitochondria
What occurs during the Krebs Cycle?
Acetyl CoA is transformed into NDH & FADH
What is the final step of cellular respiration?
Electron transport
What are the starting molecules for electron transport?
Hydrogen & ATP
What comes out from electron transport?
H2O
What happens during the electron transport?
Hydrogen is released & ATP is created
What does cellular respiration do?
Creates energy by taking in oxygen
What is the main function of fermentation?
To create energy when there is no oxygen available
What are the two types of fermentation?
Alcoholic fermentation & lactate fermentation
What happens during alcoholic fermentation?
The pyruvate from glycolysis is converted to ethanol
What are some products that use alcoholic fermentation?
Bread, beer & wine
What does lactate fermentation do?
It makes ATP quickly but not for long
What is energy?
The capacity to do work
Which are the two types of energy?
Potential & kinetic
What is potential energy?
Stored energy or energy of position (gravitational)
What is kinetic energy?
Energy of motion
What do thermodynamics say?
-Energy cannot be created or destroyed-Energy tends to spread out, disperse, until no part of a system holds more than another part
What happens during a chemical reaction?
One or more reactants become one or more products
What are reactants?
Molecules that enter the reaction and become changed by it
What are products?
Molecules produced by a reaction
In energy-requiring reactions, cells store energy where?
In the chemical bonds of organic compounds
In energy-releasing reactions, cells do what?
They retrieve energy stored in the chemical bonds of organic compounds
What is exergonic?
Energy is released
What is endergonic?
Energy is absorbed
How do cells store and retrieve energy?
By making and breaking chemical bonds
What are enzymes?
Biological catalysts, meaning they speed up reactions
Each enzyme recognizes specific what?
Reactants or substrates
What are some characteristics of an active site?
They are complementary in shape, size, polarity and charge with the enzyme’s substrates
What does the active site do?
It squeezes substrates together, influences their charge, or causes some other change that lowers activation energy
After the product leaves a reaction, what occurs with the enzyme?
Nothing; it is unchanged and the enzyme can work again
What do enzymes need?
A specific pH, temperature, and salt concentration
There are two pathways for enzymes, which?
Linear & metabolic
What do cofactors/coenzymes do?
They help enzymes by providing the energy required so they can act
What do DNA molecules and their associated proteins form?
Chromosomes
A strand of DNA is what?
A polymer of nucleotides
Which four types of nucleotides make up DNA?
Adenine, Thymine, Cytosine & Guanine
What is DNA formed out of?
Two nucleic acid strands (double helix)
How many sets of chromosomes does a human have?
23
What is the name of the process by which a cell copies its DNA?
Replication
Before DNA replication, a chromosome consists of what?
One double helix
What happens at the beginning of replication (unwinding)?
Enzymes break the hydrogen bonds that hold the double helix together, so the two DNA strands unwind and separate
During the attachment, primers serve as what?
Attachment points for DNA polymerases
What occurs during the assembling?
DNA polymerase moves along a strand of DNA, it uses the sequence of bases as a template to assemble a new strand of DNA from nucleotides
What occurs in the sealing?
The enzyme DNA ligase seals any gaps, so the new DNA strands are continuous
What is a gene?
A DNA sequence that encodes an RNA or protein product
What is gene expression?
The process of transcription and translation; the multistep process in which information encoded in a gene guides the assembly of an RNA or protein product
What happens in transcription?
Enzymes use the gene’s DNA sequence to express themselves
What happens in transcription?
A strand of DNA acts as a template, a nucleotide can be added to a growing strand of RNA only if it is complementary, each nucleotide provides the energy of its own attachment to the end of a growing strand
Where does transcription occur in eukaryotic cells?
In the nucleus
Where does transcription occur in prokaryotic cells?
In the cytoplasm
Many codons form an…?
Amino acid
Many amino acids form…?
Proteins
What are the three types of RNA?
Messenger (MRNA), Transfer (TRNA) & Ribosomal (rRNA)
What is the rRNA?
It is the main component of ribosomes, which assemble amino acids into polypeptide chains
What does the TRNA do?
It delivers the amino acids to the ribosomes
MRNA works as the messenger between what?
DNA & protein
What is the first signal in an MRNA to start translation?
AUG
AUG is codon for what?
Methionine
What does a stop codon mark?
The end of a protein-coding sequence in a MRNA
