Level 2 Biology - Life Processes at the Cellular Level

Flashcards covering key concepts from the lecture notes, including cell structure and function, prokaryotes and eukaryotes, plant vs. animal cells, organelles, enzymes, factors affecting enzymes, cell transport, diffusion, osmosis, active transport, photosynthesis, and cellular respiration.

Cell

The structural and functional unit of all living organisms; the smallest unit still classified as a living organism.

Cytoplasm

A watery fluid that contains many biomolecules & other cell components enclosed within a membrane.

Organelles

Small functional parts within cells that perform life processes; analogous to organs.

Prokaryotes

Simple, single-celled organisms lacking a nucleus and most organelles.

Eukaryotes

Organisms with cells containing a membrane-bound nucleus and specialized organelles.

Autotrophs

Producers that make their own food from the sun and other raw materials.

Heterotrophs

Consumers that obtain energy by consuming other consumers or producers.

Cellulose

Plant cells have a _ cell wall, a vacuole containing cell sap, and chloroplasts.

Cell Membrane

A protective layer that acts as a barrier and controls what moves in and out of the cell.

Chloroplasts

The site of photosynthesis in plant cells.

Catalysts

Enzymes are proteins that act as biological , speeding up reactions in living things without being changed themselves.

Active Site

The area on the enzyme where the substrate molecule fits.

Anabolic Reactions

Enzymes build molecules (e.g., proteins from amino acids).

Catabolic Reactions

Enzymes break apart molecules (e.g., digestive enzymes).

What are the two models of Enzyme Action?

Lock & Key Model and Induced Fit Model.

Denaturing

A change in the shape of the active site on an enzyme, preventing substrates from binding.

What are the 4 factors that affect enzyme activity?

Factors affecting enzyme activity include temperature, concentration, pH, and cofactors & inhibitors.

Inhibitors

Reduces or stops enzyme activity; can be competitive or non-competitive.

Passive Transport

Molecules move from areas of high concentration to low concentration; no energy is used.

Active Transport

Requires energy (ATP) to move substances across the cell membrane against the concentration gradient.

Simple Diffusion

The random movement of molecules from an area of high concentration to low concentration involving no energy.

Facilitated Diffusion

The movement of molecules from an area of high concentration to low concentration involving special transport or carrier proteins without energy expenditure.

Osmosis

The spontaneous diffusion of water from an area of high concentration to an area of low concentration across a selectively permeable membrane.

Down

Passive transport moves _ a concentration gradient, using no energy.

Hypotonic

Having a lower concentration of solute than inside the cell, causing water to move INTO the cell.

Osmoregulation

The control of water inside a cell or organism.

Active Transport

Movement of substances across the cell membrane against the concentration gradient requiring energy (ATP).

Endocytosis

The engulfing (consuming) of substances into the cell by infolding of the cell membrane.

Pinocytosis

Intake of fluids.

Phagocytosis

Intake of solids.

Exocytosis

The removal of substances from the cell.

Cuticle

Waxy layer that prevents water loss by evaporation.

Palisade Mesophyll

Rod-shaped cells with many chloroplasts found in leaves that maximize light absorption.

Photosynthesis

The chemical reaction that occurs in plants to produce food for survival. Carbon Dioxide (CO2) + Water (H2O) ---Light energy -> glucose + Oxygen (O2)

Chloroplast

The site of photosynthesis and contains chlorophyll.

Chlorophyll

A photosynthetic pigment that captures light for photosynthesis; gives leaves their green pigment.

Glucose

Photosynthesis requires raw materials like carbon dioxide and water, combined with light energy, to produce and oxygen.

Photosynthesis Equation

The chemical reaction that occurs in plants in order to convert light and water into glucose and oxygen..

What are the Chloroplast Structures?

Chloroplast structure includes thylakoid, granum, lamella, and stroma.

Enzymes

The chemical reactions in the dark phase to produce glucose are controlled by _. At high temperature enzymes are denatured.

Cellular Respiration

The conversion of biochemical energy from nutrients into usable energy (ATP) and then the release of waste products. C6H12O6 + 6O2 -> 6CO2 + 6H2O + 36ATP.

Cellular Respiration Reaction

The end product is ATP, and the by-products are Water & carbon dioxide (CO2).

State 1 - Glycolysis

It takes place in the matrix of the mitochondria, doesn’t require oxygen and happens before cellular respiration. Glucose -> Pyruvate + ATP.

Advantages and Disadvantages

Anaerobic respiration is less efficient than aerobic. The build up of lactic acid causes cramping & stops muscles from working properly. It also produces ATP very quickly and doesn’t need O2

The Transition Step

The pyruvate has to be moved into the mitochondrial matrix, this happens when it's into Acetyl CoA. This ends up with the Acetyl CoA..

State 3 – Electron Transport Chain (ETC)

Uses the energy from the Krebs Cycle to make more ATP. Hydrogens from the Krebs cycle are transported with NADH & FADH2 through the ETC = large amounts of energy, which is captured as ATP (between 30-34ATP produced). Hydrogen + Oxygen -> Water

Mitosis (General)

Used to make a new cell or repair an existing somatic cell.

DNA Components

DNA structure is a twisted ladder-like shape (double helix), and made of repeating units of nucleotides. Nucleotides are made from three segments: 1. Sugar 2. Phosphate 3. Base

DNA Replication

Semi-conservative = one side of the final DNA strand is made of the original strand, and the other is new

Replication Steps

Has two steps, the template strand and enzymes, Factors that can affect replication = temperature, amount of nucleotides (substrate), amount of enzymes.

Mitosis (Specific)

Takes place in four steps

Mitosis Stages

It is vital that any new cells produced for somatic cells contain an identical set of genetic information, E.g., skin cell, stomach cells, blood cells, etc. It results in 2 identical daughter cells.